From c1603e96719150625a8f53748703dd83e9681ede Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 7 Aug 2014 13:42:47 -0600
Subject: Change CONFIG_MSEC_PER_TICK to CONFIG_USEC_PER_TICK.  This gives more
 options for system timers in general, but more importantly, let's us realize
 higher resolution for the case of CONFIG_SCHED_TICKLESS=y -- of course, at
 the risk of some new interger overvflow problems

---
 nuttx/Documentation/NuttxPortingGuide.html         | 16 ++++-----
 nuttx/arch/avr/src/at32uc3/at32uc3_timerisr.c      | 10 +++---
 nuttx/arch/avr/src/at90usb/at90usb_timerisr.c      |  2 +-
 nuttx/arch/avr/src/atmega/atmega_timerisr.c        |  2 +-
 nuttx/arch/rgmp/src/rgmp.c                         |  6 ++--
 nuttx/configs/16z/nsh/defconfig                    |  2 +-
 nuttx/configs/amber/hello/defconfig                |  2 +-
 nuttx/configs/arduino-due/nsh/defconfig            |  2 +-
 nuttx/configs/avr32dev1/nsh/defconfig              |  2 +-
 nuttx/configs/avr32dev1/ostest/defconfig           |  2 +-
 nuttx/configs/c5471evm/httpd/defconfig             |  2 +-
 nuttx/configs/c5471evm/nettest/defconfig           |  2 +-
 nuttx/configs/c5471evm/nsh/defconfig               |  2 +-
 nuttx/configs/cloudctrl/nsh/defconfig              |  2 +-
 nuttx/configs/compal_e86/nsh_highram/defconfig     |  2 +-
 nuttx/configs/compal_e88/nsh_highram/defconfig     |  2 +-
 nuttx/configs/compal_e99/nsh_compalram/defconfig   |  2 +-
 nuttx/configs/compal_e99/nsh_highram/defconfig     |  2 +-
 nuttx/configs/demo9s12ne64/ostest/defconfig        |  2 +-
 nuttx/configs/ea3131/nsh/defconfig                 |  2 +-
 nuttx/configs/ea3131/pgnsh/defconfig               |  2 +-
 nuttx/configs/ea3131/usbserial/defconfig           |  2 +-
 nuttx/configs/ea3152/ostest/defconfig              |  2 +-
 nuttx/configs/eagle100/httpd/defconfig             |  2 +-
 nuttx/configs/eagle100/nettest/defconfig           |  2 +-
 nuttx/configs/eagle100/nsh/defconfig               |  2 +-
 nuttx/configs/eagle100/nxflat/defconfig            |  2 +-
 nuttx/configs/eagle100/thttpd/defconfig            |  2 +-
 nuttx/configs/ekk-lm3s9b96/nsh/defconfig           |  2 +-
 nuttx/configs/ez80f910200kitg/ostest/defconfig     |  2 +-
 nuttx/configs/ez80f910200zco/dhcpd/defconfig       |  2 +-
 nuttx/configs/ez80f910200zco/httpd/defconfig       |  2 +-
 nuttx/configs/ez80f910200zco/nettest/defconfig     |  2 +-
 nuttx/configs/ez80f910200zco/nsh/defconfig         |  2 +-
 nuttx/configs/ez80f910200zco/poll/defconfig        |  2 +-
 nuttx/configs/fire-stm32v2/nsh/defconfig           |  2 +-
 nuttx/configs/freedom-kl25z/minnsh/defconfig       |  2 +-
 nuttx/configs/freedom-kl25z/nsh/defconfig          |  2 +-
 nuttx/configs/hymini-stm32v/buttons/defconfig      |  2 +-
 nuttx/configs/hymini-stm32v/nsh/defconfig          |  2 +-
 nuttx/configs/hymini-stm32v/nsh2/defconfig         |  2 +-
 nuttx/configs/hymini-stm32v/usbmsc/defconfig       |  2 +-
 nuttx/configs/hymini-stm32v/usbnsh/defconfig       |  2 +-
 nuttx/configs/hymini-stm32v/usbserial/defconfig    |  2 +-
 nuttx/configs/kwikstik-k40/ostest/defconfig        |  2 +-
 nuttx/configs/lincoln60/nsh/defconfig              |  2 +-
 nuttx/configs/lm3s6432-s2e/nsh/defconfig           |  2 +-
 nuttx/configs/lm3s6965-ek/discover/defconfig       |  2 +-
 nuttx/configs/lm3s6965-ek/nsh/defconfig            |  2 +-
 nuttx/configs/lm3s6965-ek/nx/defconfig             |  2 +-
 nuttx/configs/lm3s6965-ek/tcpecho/defconfig        |  2 +-
 nuttx/configs/lm3s8962-ek/nsh/defconfig            |  2 +-
 nuttx/configs/lm3s8962-ek/nx/defconfig             |  2 +-
 nuttx/configs/lm4f120-launchpad/nsh/defconfig      |  2 +-
 nuttx/configs/lpc4330-xplorer/nsh/defconfig        |  2 +-
 nuttx/configs/lpcxpresso-lpc1768/dhcpd/defconfig   |  2 +-
 nuttx/configs/lpcxpresso-lpc1768/nsh/defconfig     |  2 +-
 nuttx/configs/lpcxpresso-lpc1768/nx/defconfig      |  2 +-
 nuttx/configs/lpcxpresso-lpc1768/thttpd/defconfig  |  2 +-
 nuttx/configs/lpcxpresso-lpc1768/usbmsc/defconfig  |  2 +-
 nuttx/configs/maple/nsh/defconfig                  |  2 +-
 nuttx/configs/maple/nx/defconfig                   |  2 +-
 nuttx/configs/maple/usbnsh/defconfig               |  2 +-
 nuttx/configs/mbed/hidkbd/defconfig                |  2 +-
 nuttx/configs/mbed/nsh/defconfig                   |  2 +-
 nuttx/configs/mcu123-lpc214x/composite/defconfig   |  2 +-
 nuttx/configs/mcu123-lpc214x/nsh/defconfig         |  2 +-
 nuttx/configs/mcu123-lpc214x/usbmsc/defconfig      |  2 +-
 nuttx/configs/mcu123-lpc214x/usbserial/defconfig   |  2 +-
 nuttx/configs/micropendous3/hello/defconfig        |  2 +-
 nuttx/configs/mikroe-stm32f4/fulldemo/defconfig    |  2 +-
 nuttx/configs/mikroe-stm32f4/kostest/defconfig     |  2 +-
 nuttx/configs/mikroe-stm32f4/nsh/defconfig         |  2 +-
 nuttx/configs/mikroe-stm32f4/nx/defconfig          |  2 +-
 nuttx/configs/mikroe-stm32f4/nxlines/defconfig     |  2 +-
 nuttx/configs/mikroe-stm32f4/nxtext/defconfig      |  2 +-
 nuttx/configs/mikroe-stm32f4/usbnsh/defconfig      |  2 +-
 nuttx/configs/mirtoo/nsh/defconfig                 |  2 +-
 nuttx/configs/mirtoo/nxffs/defconfig               |  2 +-
 nuttx/configs/mx1ads/ostest/defconfig              |  2 +-
 nuttx/configs/ne64badge/ostest/defconfig           |  2 +-
 nuttx/configs/ntosd-dm320/nettest/defconfig        |  2 +-
 nuttx/configs/ntosd-dm320/nsh/defconfig            |  2 +-
 nuttx/configs/ntosd-dm320/poll/defconfig           |  2 +-
 nuttx/configs/ntosd-dm320/thttpd/defconfig         |  2 +-
 nuttx/configs/ntosd-dm320/udp/defconfig            |  2 +-
 nuttx/configs/ntosd-dm320/webserver/defconfig      |  2 +-
 nuttx/configs/nucleo-f401re/nsh/defconfig          |  2 +-
 nuttx/configs/nucleus2g/nsh/defconfig              |  2 +-
 nuttx/configs/nucleus2g/usbmsc/defconfig           |  2 +-
 nuttx/configs/nucleus2g/usbserial/defconfig        |  2 +-
 nuttx/configs/nutiny-nuc120/nsh/defconfig          |  2 +-
 nuttx/configs/olimex-lpc-h3131/nsh/defconfig       |  2 +-
 nuttx/configs/olimex-lpc1766stk/ftpc/defconfig     |  2 +-
 nuttx/configs/olimex-lpc1766stk/hidkbd/defconfig   |  2 +-
 nuttx/configs/olimex-lpc1766stk/hidmouse/defconfig |  2 +-
 nuttx/configs/olimex-lpc1766stk/nettest/defconfig  |  2 +-
 nuttx/configs/olimex-lpc1766stk/nsh/defconfig      |  2 +-
 nuttx/configs/olimex-lpc1766stk/nx/defconfig       |  2 +-
 .../configs/olimex-lpc1766stk/slip-httpd/defconfig |  2 +-
 nuttx/configs/olimex-lpc1766stk/thttpd/defconfig   |  2 +-
 nuttx/configs/olimex-lpc1766stk/usbmsc/defconfig   |  2 +-
 .../configs/olimex-lpc1766stk/usbserial/defconfig  |  2 +-
 nuttx/configs/olimex-lpc1766stk/zmodem/defconfig   |  2 +-
 nuttx/configs/olimex-lpc2378/nsh/defconfig         |  2 +-
 nuttx/configs/olimex-stm32-h405/nshusb/defconfig   |  2 +-
 nuttx/configs/olimex-stm32-p107/nsh/defconfig      |  2 +-
 nuttx/configs/olimex-stm32-p207/nsh/defconfig      |  2 +-
 nuttx/configs/olimex-strp711/nettest/defconfig     |  2 +-
 nuttx/configs/olimex-strp711/nsh/defconfig         |  2 +-
 nuttx/configs/open1788/knsh/defconfig              |  2 +-
 nuttx/configs/open1788/nsh/defconfig               |  2 +-
 nuttx/configs/open1788/nxlines/defconfig           |  2 +-
 nuttx/configs/p112/ostest/defconfig                |  2 +-
 nuttx/configs/pcblogic-pic32mx/nsh/defconfig       |  2 +-
 nuttx/configs/pcduino-a10/nsh/defconfig            |  2 +-
 nuttx/configs/pic32-starterkit/nsh/defconfig       |  2 +-
 nuttx/configs/pic32-starterkit/nsh2/defconfig      |  2 +-
 nuttx/configs/pic32mx7mmb/nsh/defconfig            |  2 +-
 nuttx/configs/pirelli_dpl10/nsh_highram/defconfig  |  2 +-
 nuttx/configs/pjrc-8051/defconfig                  |  2 +-
 nuttx/configs/px4fmu-v2_upstream/nsh/defconfig     |  2 +-
 nuttx/configs/qemu-i486/nsh/defconfig              |  2 +-
 nuttx/configs/qemu-i486/ostest/defconfig           |  2 +-
 nuttx/configs/rgmp/arm/default/defconfig           |  2 +-
 nuttx/configs/rgmp/arm/nsh/defconfig               |  2 +-
 nuttx/configs/rgmp/x86/cxxtest/defconfig           |  2 +-
 nuttx/configs/rgmp/x86/default/defconfig           |  2 +-
 nuttx/configs/rgmp/x86/helloxx/defconfig           |  2 +-
 nuttx/configs/rgmp/x86/nsh/defconfig               |  2 +-
 nuttx/configs/sam3u-ek/knsh/defconfig              |  2 +-
 nuttx/configs/sam3u-ek/nsh/defconfig               |  2 +-
 nuttx/configs/sam3u-ek/nx/defconfig                |  2 +-
 nuttx/configs/sam3u-ek/nxwm/defconfig              |  2 +-
 nuttx/configs/sam4e-ek/nsh/defconfig               |  2 +-
 nuttx/configs/sam4e-ek/usbnsh/defconfig            |  2 +-
 nuttx/configs/sam4l-xplained/nsh/defconfig         |  2 +-
 nuttx/configs/sam4s-xplained-pro/nsh/defconfig     |  2 +-
 nuttx/configs/sam4s-xplained/nsh/defconfig         |  2 +-
 nuttx/configs/sama5d3-xplained/nsh/defconfig       |  2 +-
 nuttx/configs/sama5d3x-ek/demo/defconfig           |  2 +-
 nuttx/configs/sama5d3x-ek/hello/defconfig          |  2 +-
 nuttx/configs/sama5d3x-ek/norboot/defconfig        |  2 +-
 nuttx/configs/sama5d3x-ek/nsh/defconfig            |  2 +-
 nuttx/configs/sama5d3x-ek/nx/defconfig             |  2 +-
 nuttx/configs/sama5d3x-ek/nxplayer/defconfig       |  2 +-
 nuttx/configs/sama5d3x-ek/nxwm/defconfig           |  2 +-
 nuttx/configs/sama5d3x-ek/ov2640/defconfig         |  2 +-
 nuttx/configs/sama5d4-ek/at25boot/defconfig        |  2 +-
 nuttx/configs/sama5d4-ek/dramboot/defconfig        |  2 +-
 nuttx/configs/sama5d4-ek/nsh/defconfig             |  2 +-
 nuttx/configs/sama5d4-ek/nxwm/defconfig            |  2 +-
 nuttx/configs/sama5d4-ek/ramtest/defconfig         |  2 +-
 nuttx/configs/samd20-xplained/nsh/defconfig        |  2 +-
 nuttx/configs/shenzhou/nsh/defconfig               |  2 +-
 nuttx/configs/shenzhou/nxwm/defconfig              |  2 +-
 nuttx/configs/shenzhou/thttpd/defconfig            |  2 +-
 nuttx/configs/sim/configdata/defconfig             |  2 +-
 nuttx/configs/sim/cxxtest/defconfig                |  2 +-
 nuttx/configs/sim/mount/defconfig                  |  2 +-
 nuttx/configs/sim/mtdpart/defconfig                |  2 +-
 nuttx/configs/sim/nettest/defconfig                |  2 +-
 nuttx/configs/sim/nsh/defconfig                    |  2 +-
 nuttx/configs/sim/nsh2/defconfig                   |  2 +-
 nuttx/configs/sim/nx/defconfig                     |  2 +-
 nuttx/configs/sim/nx11/defconfig                   |  2 +-
 nuttx/configs/sim/nxffs/defconfig                  |  2 +-
 nuttx/configs/sim/nxlines/defconfig                |  2 +-
 nuttx/configs/sim/nxwm/defconfig                   |  2 +-
 nuttx/configs/sim/ostest/defconfig                 |  2 +-
 nuttx/configs/sim/pashello/defconfig               |  2 +-
 nuttx/configs/sim/touchscreen/defconfig            |  2 +-
 nuttx/configs/skp16c26/ostest/defconfig            |  2 +-
 nuttx/configs/spark/composite/defconfig            |  2 +-
 nuttx/configs/spark/nsh/defconfig                  |  2 +-
 nuttx/configs/spark/usbmsc/defconfig               |  2 +-
 nuttx/configs/spark/usbnsh/defconfig               |  2 +-
 nuttx/configs/spark/usbserial/defconfig            |  2 +-
 nuttx/configs/stm3210e-eval/buttons/defconfig      |  2 +-
 nuttx/configs/stm3210e-eval/composite/defconfig    |  2 +-
 nuttx/configs/stm3210e-eval/nsh/defconfig          |  2 +-
 nuttx/configs/stm3210e-eval/nsh2/defconfig         |  2 +-
 nuttx/configs/stm3210e-eval/nx/defconfig           |  2 +-
 nuttx/configs/stm3210e-eval/nxconsole/defconfig    |  2 +-
 nuttx/configs/stm3210e-eval/pm/defconfig           |  2 +-
 nuttx/configs/stm3210e-eval/usbmsc/defconfig       |  2 +-
 nuttx/configs/stm3210e-eval/usbserial/defconfig    |  2 +-
 nuttx/configs/stm3220g-eval/dhcpd/defconfig        |  2 +-
 nuttx/configs/stm3220g-eval/nettest/defconfig      |  2 +-
 nuttx/configs/stm3220g-eval/nsh/defconfig          |  2 +-
 nuttx/configs/stm3220g-eval/nsh2/defconfig         |  2 +-
 nuttx/configs/stm3220g-eval/nxwm/defconfig         |  2 +-
 nuttx/configs/stm3220g-eval/telnetd/defconfig      |  2 +-
 nuttx/configs/stm3240g-eval/dhcpd/defconfig        |  2 +-
 nuttx/configs/stm3240g-eval/discover/defconfig     |  2 +-
 nuttx/configs/stm3240g-eval/knxwm/defconfig        |  2 +-
 nuttx/configs/stm3240g-eval/nettest/defconfig      |  2 +-
 nuttx/configs/stm3240g-eval/nsh/defconfig          |  2 +-
 nuttx/configs/stm3240g-eval/nsh2/defconfig         |  2 +-
 nuttx/configs/stm3240g-eval/nxconsole/defconfig    |  2 +-
 nuttx/configs/stm3240g-eval/nxwm/defconfig         |  2 +-
 nuttx/configs/stm3240g-eval/telnetd/defconfig      |  2 +-
 nuttx/configs/stm3240g-eval/webserver/defconfig    |  2 +-
 nuttx/configs/stm3240g-eval/xmlrpc/defconfig       |  2 +-
 nuttx/configs/stm32_tiny/nsh/defconfig             |  2 +-
 nuttx/configs/stm32_tiny/usbnsh/defconfig          |  2 +-
 nuttx/configs/stm32f100rc_generic/nsh/defconfig    |  2 +-
 nuttx/configs/stm32f3discovery/nsh/defconfig       |  2 +-
 nuttx/configs/stm32f3discovery/usbnsh/defconfig    |  2 +-
 nuttx/configs/stm32f429i-disco/extflash/defconfig  |  2 +-
 nuttx/configs/stm32f429i-disco/nsh/defconfig       |  2 +-
 nuttx/configs/stm32f429i-disco/usbmsc/defconfig    |  2 +-
 nuttx/configs/stm32f429i-disco/usbnsh/defconfig    |  2 +-
 nuttx/configs/stm32f4discovery/cxxtest/defconfig   |  2 +-
 nuttx/configs/stm32f4discovery/elf/defconfig       |  2 +-
 nuttx/configs/stm32f4discovery/kostest/defconfig   |  2 +-
 nuttx/configs/stm32f4discovery/nsh/defconfig       |  2 +-
 nuttx/configs/stm32f4discovery/nxlines/defconfig   |  2 +-
 nuttx/configs/stm32f4discovery/pm/defconfig        |  2 +-
 .../configs/stm32f4discovery/posix_spawn/defconfig |  2 +-
 nuttx/configs/stm32f4discovery/usbnsh/defconfig    |  2 +-
 nuttx/configs/stm32f4discovery/winbuild/defconfig  |  2 +-
 nuttx/configs/stm32ldiscovery/nsh/defconfig        |  2 +-
 nuttx/configs/stm32vldiscovery/nsh/defconfig       |  2 +-
 nuttx/configs/sure-pic32mx/nsh/defconfig           |  2 +-
 nuttx/configs/sure-pic32mx/usbnsh/defconfig        |  2 +-
 nuttx/configs/teensy/hello/defconfig               |  2 +-
 nuttx/configs/teensy/nsh/defconfig                 |  2 +-
 nuttx/configs/teensy/usbmsc/defconfig              |  2 +-
 nuttx/configs/tm4c123g-launchpad/nsh/defconfig     |  2 +-
 nuttx/configs/twr-k60n512/nsh/defconfig            |  2 +-
 nuttx/configs/ubw32/nsh/defconfig                  |  2 +-
 nuttx/configs/us7032evb1/nsh/defconfig             |  2 +-
 nuttx/configs/us7032evb1/ostest/defconfig          |  2 +-
 nuttx/configs/viewtool-stm32f107/highpri/defconfig |  2 +-
 nuttx/configs/viewtool-stm32f107/netnsh/defconfig  |  2 +-
 nuttx/configs/viewtool-stm32f107/nsh/defconfig     |  2 +-
 nuttx/configs/vsn/nsh/defconfig                    |  2 +-
 nuttx/configs/xtrs/nsh/defconfig                   |  2 +-
 nuttx/configs/xtrs/ostest/defconfig                |  2 +-
 nuttx/configs/xtrs/pashello/defconfig              |  2 +-
 nuttx/configs/z16f2800100zcog/nsh/defconfig        |  2 +-
 nuttx/configs/z16f2800100zcog/ostest/defconfig     |  2 +-
 nuttx/configs/z16f2800100zcog/pashello/defconfig   |  2 +-
 nuttx/configs/z80sim/nsh/defconfig                 |  2 +-
 nuttx/configs/z80sim/ostest/defconfig              |  2 +-
 nuttx/configs/z80sim/pashello/defconfig            |  2 +-
 nuttx/configs/z8encore000zco/ostest/defconfig      |  2 +-
 nuttx/configs/z8f64200100kit/ostest/defconfig      |  2 +-
 nuttx/configs/zkit-arm-1769/hello/defconfig        |  2 +-
 nuttx/configs/zkit-arm-1769/nsh/defconfig          |  2 +-
 nuttx/configs/zkit-arm-1769/nxhello/defconfig      |  2 +-
 nuttx/configs/zkit-arm-1769/thttpd/defconfig       |  2 +-
 nuttx/configs/zp214xpa/nsh/defconfig               |  2 +-
 nuttx/configs/zp214xpa/nxlines/defconfig           |  2 +-
 nuttx/include/limits.h                             | 17 +++++-----
 nuttx/include/nuttx/clock.h                        | 39 +++++++++++++++-------
 nuttx/include/time.h                               |  8 ++---
 nuttx/sched/Kconfig                                | 32 ++++++++++++------
 259 files changed, 331 insertions(+), 301 deletions(-)

diff --git a/nuttx/Documentation/NuttxPortingGuide.html b/nuttx/Documentation/NuttxPortingGuide.html
index 0f54a3e87..8eb13e297 100644
--- a/nuttx/Documentation/NuttxPortingGuide.html
+++ b/nuttx/Documentation/NuttxPortingGuide.html
@@ -2220,23 +2220,23 @@ The system can be re-made subsequently by just typing <code>make</code>.
 
 <p><b>System Timer</b>
   In most implementations, system time is provided by a timer interrupt.
-  That timer interrupt runs at rate determined by <code>CONFIG_MSEC_PER_TICKS</code> (default 10 or 100Hz).
-  The timer generates an interrupt each <code>CONFIG_MSEC_PER_TICKS</code> milliseconds and increments a counter called <code>g_system_timer</code>.
-  <code>g_system_timer</code> then provides a time-base for calculating <i>up-time</i> and elapsed time intervals in units of <code>CONFIG_MSEC_PER_TICKS</code>.
+  That timer interrupt runs at rate determined by <code>CONFIG_USEC_PER_TICKS</code> (default 10000 microseconds or 100Hz.  If <code>CONFIG_SCHED_TICKLESS</code> is selected, the default is 100 microseconds).
+  The timer generates an interrupt each <code>CONFIG_USEC_PER_TICKS</code> microseconds and increments a counter called <code>g_system_timer</code>.
+  <code>g_system_timer</code> then provides a time-base for calculating <i>up-time</i> and elapsed time intervals in units of <code>CONFIG_USEC_PER_TICKS</code>.
   The range of <code>g_system_timer</code> is, by default, 32-bits.
   However, if the MCU supports type <code>long long</code> and <code>CONFIG_SYSTEM_TIME16</code> is selected,
   a 64-bit system timer will be supported instead.
 </p>
 <p><b>System Timer Accuracy</b>
-  On many system, the exact timer interval specified by <code>CONFIG_MSEC_PER_TICKS</code> cannot be achieved due to limitations in frequencies or in dividers.
-  As a result, the time interval specified by <code>CONFIG_MSEC_PER_TICKS</code> may only be approximate and there may be small errors in the apparent <i>up-time</i> time.
+  On many system, the exact timer interval specified by <code>CONFIG_USEC_PER_TICKS</code> cannot be achieved due to limitations in frequencies or in dividers.
+  As a result, the time interval specified by <code>CONFIG_USEC_PER_TICKS</code> may only be approximate and there may be small errors in the apparent <i>up-time</i> time.
   These small errors, however, will accumulate over time and after a long period of time may have an unacceptably large error in the apparent <i>up-time</i> of the MCU.
 </p>
-  If the timer tick period generated by the hardware is not exactly <code>CONFIG_MSEC_PER_TICKS</code> <i>and</i> if there you require accurate up-time for the MCU, then there are measures that you can take:
+  If the timer tick period generated by the hardware is not exactly <code>CONFIG_USEC_PER_TICKS</code> <i>and</i> if there you require accurate up-time for the MCU, then there are measures that you can take:
 </p>
 <ul>
   <li>
-    Perhaps you can adjust <code>CONFIG_MSEC_PER_TICKS</code> to a different value so that an exactly <code>CONFIG_MSEC_PER_TICKS</code> can be accomplished.
+    Perhaps you can adjust <code>CONFIG_USEC_PER_TICKS</code> to a different value so that an exactly <code>CONFIG_USEC_PER_TICKS</code> can be realized.
   </li>
   <li>
     Or you can use a technique known as <i>Delta-Sigma Modulation</i>. (Suggested by Uros Platise).  Consider the example below.
@@ -2247,7 +2247,7 @@ The system can be re-made subsequently by just typing <code>make</code>.
   Consider this case:  The system timer is a count-up timer driven at 32.768KHz.
   There are dividers that can be used, but a divider of one yields the highest accuracy.
   This counter counts up until the count equals a match value, then a timer interrupt is generated.
-  The desire frequency is 100Hz (<code>CONFIG_MSEC_PER_TICKS</code> is 10).
+  The desire frequency is 100Hz (<code>CONFIG_USEC_PER_TICKS</code> is 10000).
 </p>
 <p>
   This exact frequency of 100Hz cannot be obtained in this case.
diff --git a/nuttx/arch/avr/src/at32uc3/at32uc3_timerisr.c b/nuttx/arch/avr/src/at32uc3/at32uc3_timerisr.c
index b12f8e264..160c3e6b3 100644
--- a/nuttx/arch/avr/src/at32uc3/at32uc3_timerisr.c
+++ b/nuttx/arch/avr/src/at32uc3/at32uc3_timerisr.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/avr/src/at32uc3/at32uc3_timerisr.c
  *
- *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2010, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -61,12 +61,12 @@
  * setting that defaults to 100 (100 ticks per second = 10 MS interval).
  *
  * However, the AVR RTC does not support that default value well and so, we
- * will insist that default is over-ridden by CONFIG_MSEC_PER_TICK in the
- * configuration file.  Further, we will insist that CONFIG_MSEC_PER_TICK
- * have the value 8 (see reasoning below).
+ * will insist that default is over-ridden by CONFIG_USEC_PER_TICK in the
+ * configuration file.  Further, we will insist that CONFIG_USEC_PER_TICK
+ * have the value 10000 (see reasoning below).
  */
 
-#if defined(CONFIG_MSEC_PER_TICK) && CONFIG_MSEC_PER_TICK != 10
+#if defined(CONFIG_USEC_PER_TICK) && CONFIG_USEC_PER_TICK != 10000
 #  error "Only a 100KHz system clock is supported"
 #endif
 
diff --git a/nuttx/arch/avr/src/at90usb/at90usb_timerisr.c b/nuttx/arch/avr/src/at90usb/at90usb_timerisr.c
index a6e82b604..9bd4514e9 100644
--- a/nuttx/arch/avr/src/at90usb/at90usb_timerisr.c
+++ b/nuttx/arch/avr/src/at90usb/at90usb_timerisr.c
@@ -56,7 +56,7 @@
  ****************************************************************************/
 
 /* The CPU frequency is given by BOARD_CPU_CLOCK (defined in board.h).  The
- * desired interrupt frequency is given by CONFIG_MSEC_PER_TICK.  An unscaled
+ * desired interrupt frequency is given by CONFIG_USEC_PER_TICK.  An unscaled
  * ideal match is given by:
  *
  *   CLOCK = CPU_CLOCK / DIVISOR                      # CPU clocks/sec
diff --git a/nuttx/arch/avr/src/atmega/atmega_timerisr.c b/nuttx/arch/avr/src/atmega/atmega_timerisr.c
index 4c3ada87b..069935fb0 100644
--- a/nuttx/arch/avr/src/atmega/atmega_timerisr.c
+++ b/nuttx/arch/avr/src/atmega/atmega_timerisr.c
@@ -56,7 +56,7 @@
  ****************************************************************************/
 
 /* The CPU frequency is given by BOARD_CPU_CLOCK (defined in board.h).  The
- * desired interrupt frequency is given by CONFIG_MSEC_PER_TICK.  An unscaled
+ * desired interrupt frequency is given by CONFIG_USEC_PER_TICK.  An unscaled
  * ideal match is given by:
  *
  *   CLOCK = CPU_CLOCK / DIVISOR                      # CPU clocks/sec
diff --git a/nuttx/arch/rgmp/src/rgmp.c b/nuttx/arch/rgmp/src/rgmp.c
index 495c5e05c..652e11cca 100644
--- a/nuttx/arch/rgmp/src/rgmp.c
+++ b/nuttx/arch/rgmp/src/rgmp.c
@@ -46,6 +46,8 @@
 #include <nuttx/arch.h>
 #include <nuttx/sched.h>
 #include <nuttx/kmalloc.h>
+#include <nuttx/clock.h>
+
 #include <semaphore.h>
 #include <queue.h>
 #include <stdlib.h>
@@ -55,8 +57,8 @@
 int nest_irq = 0;
 
 // the default time is 10ms
-#ifdef CONFIG_MSEC_PER_TICK
-const unsigned int rtos_tick_time = CONFIG_MSEC_PER_TICK;
+#ifdef MSEC_PER_TICK
+const unsigned int rtos_tick_time = MSEC_PER_TICK;
 #else
 const unsigned int rtos_tick_time = 10;
 #endif
diff --git a/nuttx/configs/16z/nsh/defconfig b/nuttx/configs/16z/nsh/defconfig
index 10a609d29..396fe13e7 100644
--- a/nuttx/configs/16z/nsh/defconfig
+++ b/nuttx/configs/16z/nsh/defconfig
@@ -192,7 +192,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/amber/hello/defconfig b/nuttx/configs/amber/hello/defconfig
index 6cfcbd223..823c916ef 100644
--- a/nuttx/configs/amber/hello/defconfig
+++ b/nuttx/configs/amber/hello/defconfig
@@ -155,7 +155,7 @@ CONFIG_ARCH_BOARD="amber"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/arduino-due/nsh/defconfig b/nuttx/configs/arduino-due/nsh/defconfig
index 9b6c51f27..3f376b118 100644
--- a/nuttx/configs/arduino-due/nsh/defconfig
+++ b/nuttx/configs/arduino-due/nsh/defconfig
@@ -250,7 +250,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/avr32dev1/nsh/defconfig b/nuttx/configs/avr32dev1/nsh/defconfig
index 91225516e..425aeb269 100644
--- a/nuttx/configs/avr32dev1/nsh/defconfig
+++ b/nuttx/configs/avr32dev1/nsh/defconfig
@@ -185,7 +185,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/avr32dev1/ostest/defconfig b/nuttx/configs/avr32dev1/ostest/defconfig
index 48a6ba489..556391b41 100644
--- a/nuttx/configs/avr32dev1/ostest/defconfig
+++ b/nuttx/configs/avr32dev1/ostest/defconfig
@@ -184,7 +184,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/c5471evm/httpd/defconfig b/nuttx/configs/c5471evm/httpd/defconfig
index fa2e62204..dae30de76 100644
--- a/nuttx/configs/c5471evm/httpd/defconfig
+++ b/nuttx/configs/c5471evm/httpd/defconfig
@@ -208,7 +208,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/c5471evm/nettest/defconfig b/nuttx/configs/c5471evm/nettest/defconfig
index 08384dc4b..cedfc4f25 100644
--- a/nuttx/configs/c5471evm/nettest/defconfig
+++ b/nuttx/configs/c5471evm/nettest/defconfig
@@ -207,7 +207,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/c5471evm/nsh/defconfig b/nuttx/configs/c5471evm/nsh/defconfig
index 34d236c40..1d3fb01f8 100644
--- a/nuttx/configs/c5471evm/nsh/defconfig
+++ b/nuttx/configs/c5471evm/nsh/defconfig
@@ -209,7 +209,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/cloudctrl/nsh/defconfig b/nuttx/configs/cloudctrl/nsh/defconfig
index 6ed416c9b..811fbdb1f 100644
--- a/nuttx/configs/cloudctrl/nsh/defconfig
+++ b/nuttx/configs/cloudctrl/nsh/defconfig
@@ -253,7 +253,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=1
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/compal_e86/nsh_highram/defconfig b/nuttx/configs/compal_e86/nsh_highram/defconfig
index 9d33cd37c..f5804939d 100644
--- a/nuttx/configs/compal_e86/nsh_highram/defconfig
+++ b/nuttx/configs/compal_e86/nsh_highram/defconfig
@@ -191,7 +191,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/compal_e88/nsh_highram/defconfig b/nuttx/configs/compal_e88/nsh_highram/defconfig
index b74e6bfad..7dd3a4d8e 100644
--- a/nuttx/configs/compal_e88/nsh_highram/defconfig
+++ b/nuttx/configs/compal_e88/nsh_highram/defconfig
@@ -206,7 +206,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/compal_e99/nsh_compalram/defconfig b/nuttx/configs/compal_e99/nsh_compalram/defconfig
index 31bacebac..ad634c52a 100644
--- a/nuttx/configs/compal_e99/nsh_compalram/defconfig
+++ b/nuttx/configs/compal_e99/nsh_compalram/defconfig
@@ -209,7 +209,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/compal_e99/nsh_highram/defconfig b/nuttx/configs/compal_e99/nsh_highram/defconfig
index e1a2a4ec5..7045905da 100644
--- a/nuttx/configs/compal_e99/nsh_highram/defconfig
+++ b/nuttx/configs/compal_e99/nsh_highram/defconfig
@@ -209,7 +209,7 @@ CONFIG_COMPALE99_LCD_SSD1783=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/demo9s12ne64/ostest/defconfig b/nuttx/configs/demo9s12ne64/ostest/defconfig
index f32263476..725d84a32 100644
--- a/nuttx/configs/demo9s12ne64/ostest/defconfig
+++ b/nuttx/configs/demo9s12ne64/ostest/defconfig
@@ -164,7 +164,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ea3131/nsh/defconfig b/nuttx/configs/ea3131/nsh/defconfig
index 22e69dfcf..e7ed63090 100644
--- a/nuttx/configs/ea3131/nsh/defconfig
+++ b/nuttx/configs/ea3131/nsh/defconfig
@@ -209,7 +209,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/ea3131/pgnsh/defconfig b/nuttx/configs/ea3131/pgnsh/defconfig
index fb5e0010b..54715ec15 100644
--- a/nuttx/configs/ea3131/pgnsh/defconfig
+++ b/nuttx/configs/ea3131/pgnsh/defconfig
@@ -248,7 +248,7 @@ CONFIG_EA3131_PAGING_SPIPORT=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ea3131/usbserial/defconfig b/nuttx/configs/ea3131/usbserial/defconfig
index e2d3dd56b..bc1fb69ef 100644
--- a/nuttx/configs/ea3131/usbserial/defconfig
+++ b/nuttx/configs/ea3131/usbserial/defconfig
@@ -230,7 +230,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ea3152/ostest/defconfig b/nuttx/configs/ea3152/ostest/defconfig
index d9154ec94..c39243be0 100644
--- a/nuttx/configs/ea3152/ostest/defconfig
+++ b/nuttx/configs/ea3152/ostest/defconfig
@@ -223,7 +223,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/eagle100/httpd/defconfig b/nuttx/configs/eagle100/httpd/defconfig
index 8b3a209cb..6b1ca1a15 100644
--- a/nuttx/configs/eagle100/httpd/defconfig
+++ b/nuttx/configs/eagle100/httpd/defconfig
@@ -246,7 +246,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/eagle100/nettest/defconfig b/nuttx/configs/eagle100/nettest/defconfig
index d723dc786..d06210fb0 100644
--- a/nuttx/configs/eagle100/nettest/defconfig
+++ b/nuttx/configs/eagle100/nettest/defconfig
@@ -272,7 +272,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/eagle100/nsh/defconfig b/nuttx/configs/eagle100/nsh/defconfig
index bc93ed62c..42f383610 100644
--- a/nuttx/configs/eagle100/nsh/defconfig
+++ b/nuttx/configs/eagle100/nsh/defconfig
@@ -252,7 +252,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/eagle100/nxflat/defconfig b/nuttx/configs/eagle100/nxflat/defconfig
index 10c2aaa5a..c02753be4 100644
--- a/nuttx/configs/eagle100/nxflat/defconfig
+++ b/nuttx/configs/eagle100/nxflat/defconfig
@@ -234,7 +234,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/eagle100/thttpd/defconfig b/nuttx/configs/eagle100/thttpd/defconfig
index 4d0358682..f1176dc93 100644
--- a/nuttx/configs/eagle100/thttpd/defconfig
+++ b/nuttx/configs/eagle100/thttpd/defconfig
@@ -239,7 +239,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ekk-lm3s9b96/nsh/defconfig b/nuttx/configs/ekk-lm3s9b96/nsh/defconfig
index 0b32ad2e6..8b8a4021c 100644
--- a/nuttx/configs/ekk-lm3s9b96/nsh/defconfig
+++ b/nuttx/configs/ekk-lm3s9b96/nsh/defconfig
@@ -238,7 +238,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ez80f910200kitg/ostest/defconfig b/nuttx/configs/ez80f910200kitg/ostest/defconfig
index cc866ddd4..1df0b7927 100644
--- a/nuttx/configs/ez80f910200kitg/ostest/defconfig
+++ b/nuttx/configs/ez80f910200kitg/ostest/defconfig
@@ -207,7 +207,7 @@ CONFIG_ARCH_HAVE_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/ez80f910200zco/dhcpd/defconfig b/nuttx/configs/ez80f910200zco/dhcpd/defconfig
index 98f4e9686..41dc993c9 100644
--- a/nuttx/configs/ez80f910200zco/dhcpd/defconfig
+++ b/nuttx/configs/ez80f910200zco/dhcpd/defconfig
@@ -233,7 +233,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ez80f910200zco/httpd/defconfig b/nuttx/configs/ez80f910200zco/httpd/defconfig
index 48aef09aa..14a35bc60 100644
--- a/nuttx/configs/ez80f910200zco/httpd/defconfig
+++ b/nuttx/configs/ez80f910200zco/httpd/defconfig
@@ -234,7 +234,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ez80f910200zco/nettest/defconfig b/nuttx/configs/ez80f910200zco/nettest/defconfig
index 65553e2f8..839c715d2 100644
--- a/nuttx/configs/ez80f910200zco/nettest/defconfig
+++ b/nuttx/configs/ez80f910200zco/nettest/defconfig
@@ -233,7 +233,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ez80f910200zco/nsh/defconfig b/nuttx/configs/ez80f910200zco/nsh/defconfig
index deec47ea3..a4c42efb8 100644
--- a/nuttx/configs/ez80f910200zco/nsh/defconfig
+++ b/nuttx/configs/ez80f910200zco/nsh/defconfig
@@ -235,7 +235,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ez80f910200zco/poll/defconfig b/nuttx/configs/ez80f910200zco/poll/defconfig
index 9aa80091f..d5912e1da 100644
--- a/nuttx/configs/ez80f910200zco/poll/defconfig
+++ b/nuttx/configs/ez80f910200zco/poll/defconfig
@@ -234,7 +234,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/fire-stm32v2/nsh/defconfig b/nuttx/configs/fire-stm32v2/nsh/defconfig
index 2bcb9bf1f..762b9d470 100644
--- a/nuttx/configs/fire-stm32v2/nsh/defconfig
+++ b/nuttx/configs/fire-stm32v2/nsh/defconfig
@@ -247,7 +247,7 @@ CONFIG_ARCH_BOARD_FIRE_STM32V2=y
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/freedom-kl25z/minnsh/defconfig b/nuttx/configs/freedom-kl25z/minnsh/defconfig
index 24e859bc3..ae20fd0fa 100644
--- a/nuttx/configs/freedom-kl25z/minnsh/defconfig
+++ b/nuttx/configs/freedom-kl25z/minnsh/defconfig
@@ -210,7 +210,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/freedom-kl25z/nsh/defconfig b/nuttx/configs/freedom-kl25z/nsh/defconfig
index b8ca2777c..79c3d5e2d 100644
--- a/nuttx/configs/freedom-kl25z/nsh/defconfig
+++ b/nuttx/configs/freedom-kl25z/nsh/defconfig
@@ -215,7 +215,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/hymini-stm32v/buttons/defconfig b/nuttx/configs/hymini-stm32v/buttons/defconfig
index 41d8bdeee..0a74791fc 100644
--- a/nuttx/configs/hymini-stm32v/buttons/defconfig
+++ b/nuttx/configs/hymini-stm32v/buttons/defconfig
@@ -270,7 +270,7 @@ CONFIG_ARCH_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/hymini-stm32v/nsh/defconfig b/nuttx/configs/hymini-stm32v/nsh/defconfig
index 3329a5ac3..2020e8b1c 100644
--- a/nuttx/configs/hymini-stm32v/nsh/defconfig
+++ b/nuttx/configs/hymini-stm32v/nsh/defconfig
@@ -281,7 +281,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/hymini-stm32v/nsh2/defconfig b/nuttx/configs/hymini-stm32v/nsh2/defconfig
index c8ca2b679..0ea944817 100644
--- a/nuttx/configs/hymini-stm32v/nsh2/defconfig
+++ b/nuttx/configs/hymini-stm32v/nsh2/defconfig
@@ -295,7 +295,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/hymini-stm32v/usbmsc/defconfig b/nuttx/configs/hymini-stm32v/usbmsc/defconfig
index 4b3c6d159..af3281af4 100644
--- a/nuttx/configs/hymini-stm32v/usbmsc/defconfig
+++ b/nuttx/configs/hymini-stm32v/usbmsc/defconfig
@@ -358,7 +358,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/hymini-stm32v/usbnsh/defconfig b/nuttx/configs/hymini-stm32v/usbnsh/defconfig
index c4866289e..b908fe63e 100644
--- a/nuttx/configs/hymini-stm32v/usbnsh/defconfig
+++ b/nuttx/configs/hymini-stm32v/usbnsh/defconfig
@@ -271,7 +271,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/hymini-stm32v/usbserial/defconfig b/nuttx/configs/hymini-stm32v/usbserial/defconfig
index 7e9f1dbbd..e3a5967a5 100644
--- a/nuttx/configs/hymini-stm32v/usbserial/defconfig
+++ b/nuttx/configs/hymini-stm32v/usbserial/defconfig
@@ -349,7 +349,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/kwikstik-k40/ostest/defconfig b/nuttx/configs/kwikstik-k40/ostest/defconfig
index 39ff29145..a5e175d46 100644
--- a/nuttx/configs/kwikstik-k40/ostest/defconfig
+++ b/nuttx/configs/kwikstik-k40/ostest/defconfig
@@ -226,7 +226,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/lincoln60/nsh/defconfig b/nuttx/configs/lincoln60/nsh/defconfig
index f54880b8d..a11dbb84a 100644
--- a/nuttx/configs/lincoln60/nsh/defconfig
+++ b/nuttx/configs/lincoln60/nsh/defconfig
@@ -258,7 +258,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s6432-s2e/nsh/defconfig b/nuttx/configs/lm3s6432-s2e/nsh/defconfig
index 634fa10df..7f9cd0794 100644
--- a/nuttx/configs/lm3s6432-s2e/nsh/defconfig
+++ b/nuttx/configs/lm3s6432-s2e/nsh/defconfig
@@ -235,7 +235,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=10
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s6965-ek/discover/defconfig b/nuttx/configs/lm3s6965-ek/discover/defconfig
index 0baec5b8b..33dc59820 100644
--- a/nuttx/configs/lm3s6965-ek/discover/defconfig
+++ b/nuttx/configs/lm3s6965-ek/discover/defconfig
@@ -244,7 +244,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s6965-ek/nsh/defconfig b/nuttx/configs/lm3s6965-ek/nsh/defconfig
index 0baec5b8b..33dc59820 100644
--- a/nuttx/configs/lm3s6965-ek/nsh/defconfig
+++ b/nuttx/configs/lm3s6965-ek/nsh/defconfig
@@ -244,7 +244,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s6965-ek/nx/defconfig b/nuttx/configs/lm3s6965-ek/nx/defconfig
index ecfe5f4f6..bb236d76a 100644
--- a/nuttx/configs/lm3s6965-ek/nx/defconfig
+++ b/nuttx/configs/lm3s6965-ek/nx/defconfig
@@ -226,7 +226,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s6965-ek/tcpecho/defconfig b/nuttx/configs/lm3s6965-ek/tcpecho/defconfig
index 51b322ab7..9ef928a89 100644
--- a/nuttx/configs/lm3s6965-ek/tcpecho/defconfig
+++ b/nuttx/configs/lm3s6965-ek/tcpecho/defconfig
@@ -263,7 +263,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s8962-ek/nsh/defconfig b/nuttx/configs/lm3s8962-ek/nsh/defconfig
index 4f7789e62..96080de45 100644
--- a/nuttx/configs/lm3s8962-ek/nsh/defconfig
+++ b/nuttx/configs/lm3s8962-ek/nsh/defconfig
@@ -252,7 +252,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm3s8962-ek/nx/defconfig b/nuttx/configs/lm3s8962-ek/nx/defconfig
index 45febb5a6..cd5fe9497 100644
--- a/nuttx/configs/lm3s8962-ek/nx/defconfig
+++ b/nuttx/configs/lm3s8962-ek/nx/defconfig
@@ -234,7 +234,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lm4f120-launchpad/nsh/defconfig b/nuttx/configs/lm4f120-launchpad/nsh/defconfig
index 340295bd3..cd232a320 100644
--- a/nuttx/configs/lm4f120-launchpad/nsh/defconfig
+++ b/nuttx/configs/lm4f120-launchpad/nsh/defconfig
@@ -236,7 +236,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lpc4330-xplorer/nsh/defconfig b/nuttx/configs/lpc4330-xplorer/nsh/defconfig
index 3079a80f2..6df2f760e 100644
--- a/nuttx/configs/lpc4330-xplorer/nsh/defconfig
+++ b/nuttx/configs/lpc4330-xplorer/nsh/defconfig
@@ -264,7 +264,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/lpcxpresso-lpc1768/dhcpd/defconfig b/nuttx/configs/lpcxpresso-lpc1768/dhcpd/defconfig
index e7e14f1e5..b9d4c828b 100644
--- a/nuttx/configs/lpcxpresso-lpc1768/dhcpd/defconfig
+++ b/nuttx/configs/lpcxpresso-lpc1768/dhcpd/defconfig
@@ -281,7 +281,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/lpcxpresso-lpc1768/nsh/defconfig b/nuttx/configs/lpcxpresso-lpc1768/nsh/defconfig
index b03d2f9e3..e2d893d47 100644
--- a/nuttx/configs/lpcxpresso-lpc1768/nsh/defconfig
+++ b/nuttx/configs/lpcxpresso-lpc1768/nsh/defconfig
@@ -283,7 +283,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/lpcxpresso-lpc1768/nx/defconfig b/nuttx/configs/lpcxpresso-lpc1768/nx/defconfig
index a9176137e..da9bc9b4e 100644
--- a/nuttx/configs/lpcxpresso-lpc1768/nx/defconfig
+++ b/nuttx/configs/lpcxpresso-lpc1768/nx/defconfig
@@ -270,7 +270,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/lpcxpresso-lpc1768/thttpd/defconfig b/nuttx/configs/lpcxpresso-lpc1768/thttpd/defconfig
index 18ef5421e..c35798a4c 100644
--- a/nuttx/configs/lpcxpresso-lpc1768/thttpd/defconfig
+++ b/nuttx/configs/lpcxpresso-lpc1768/thttpd/defconfig
@@ -281,7 +281,7 @@ CONFIG_DISABLE_MQUEUE=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/lpcxpresso-lpc1768/usbmsc/defconfig b/nuttx/configs/lpcxpresso-lpc1768/usbmsc/defconfig
index 5b17b45f4..1f2bdda88 100644
--- a/nuttx/configs/lpcxpresso-lpc1768/usbmsc/defconfig
+++ b/nuttx/configs/lpcxpresso-lpc1768/usbmsc/defconfig
@@ -281,7 +281,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/maple/nsh/defconfig b/nuttx/configs/maple/nsh/defconfig
index 6b3f6ce45..ec2b4bf85 100644
--- a/nuttx/configs/maple/nsh/defconfig
+++ b/nuttx/configs/maple/nsh/defconfig
@@ -337,7 +337,7 @@ CONFIG_MAPLE_MINI=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/maple/nx/defconfig b/nuttx/configs/maple/nx/defconfig
index f1f5b5533..93c479e2b 100644
--- a/nuttx/configs/maple/nx/defconfig
+++ b/nuttx/configs/maple/nx/defconfig
@@ -361,7 +361,7 @@ CONFIG_MAPLE_MINI=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/maple/usbnsh/defconfig b/nuttx/configs/maple/usbnsh/defconfig
index 402e4dc05..fa01a4296 100644
--- a/nuttx/configs/maple/usbnsh/defconfig
+++ b/nuttx/configs/maple/usbnsh/defconfig
@@ -337,7 +337,7 @@ CONFIG_MAPLE_MINI=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/mbed/hidkbd/defconfig b/nuttx/configs/mbed/hidkbd/defconfig
index 30d281834..55b5a118f 100644
--- a/nuttx/configs/mbed/hidkbd/defconfig
+++ b/nuttx/configs/mbed/hidkbd/defconfig
@@ -270,7 +270,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/mbed/nsh/defconfig b/nuttx/configs/mbed/nsh/defconfig
index 1727ac9e5..473380d0a 100644
--- a/nuttx/configs/mbed/nsh/defconfig
+++ b/nuttx/configs/mbed/nsh/defconfig
@@ -260,7 +260,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/mcu123-lpc214x/composite/defconfig b/nuttx/configs/mcu123-lpc214x/composite/defconfig
index 737ec65c6..3020763b4 100644
--- a/nuttx/configs/mcu123-lpc214x/composite/defconfig
+++ b/nuttx/configs/mcu123-lpc214x/composite/defconfig
@@ -216,7 +216,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mcu123-lpc214x/nsh/defconfig b/nuttx/configs/mcu123-lpc214x/nsh/defconfig
index 88d14c241..1f79f478c 100644
--- a/nuttx/configs/mcu123-lpc214x/nsh/defconfig
+++ b/nuttx/configs/mcu123-lpc214x/nsh/defconfig
@@ -174,7 +174,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=1
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/mcu123-lpc214x/usbmsc/defconfig b/nuttx/configs/mcu123-lpc214x/usbmsc/defconfig
index 49b1141d0..b315b8ed8 100644
--- a/nuttx/configs/mcu123-lpc214x/usbmsc/defconfig
+++ b/nuttx/configs/mcu123-lpc214x/usbmsc/defconfig
@@ -215,7 +215,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mcu123-lpc214x/usbserial/defconfig b/nuttx/configs/mcu123-lpc214x/usbserial/defconfig
index 8c20ea6f4..b9613f963 100644
--- a/nuttx/configs/mcu123-lpc214x/usbserial/defconfig
+++ b/nuttx/configs/mcu123-lpc214x/usbserial/defconfig
@@ -216,7 +216,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/micropendous3/hello/defconfig b/nuttx/configs/micropendous3/hello/defconfig
index eb82914b8..fab5d8c31 100644
--- a/nuttx/configs/micropendous3/hello/defconfig
+++ b/nuttx/configs/micropendous3/hello/defconfig
@@ -163,7 +163,7 @@ CONFIG_ARCH_BOARD="micropendous3"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/fulldemo/defconfig b/nuttx/configs/mikroe-stm32f4/fulldemo/defconfig
index 5e81ecd1f..524c67b59 100644
--- a/nuttx/configs/mikroe-stm32f4/fulldemo/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/fulldemo/defconfig
@@ -412,7 +412,7 @@ CONFIG_MIKROE_FLASH_PART_LIST="8,248,768"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/kostest/defconfig b/nuttx/configs/mikroe-stm32f4/kostest/defconfig
index 39e660408..e1ae1fcb9 100644
--- a/nuttx/configs/mikroe-stm32f4/kostest/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/kostest/defconfig
@@ -386,7 +386,7 @@ CONFIG_MIKROE_FLASH_PART_LIST="256,768"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/nsh/defconfig b/nuttx/configs/mikroe-stm32f4/nsh/defconfig
index 8c8beb9e0..faa57c428 100644
--- a/nuttx/configs/mikroe-stm32f4/nsh/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/nsh/defconfig
@@ -377,7 +377,7 @@ CONFIG_MIKROE_FLASH_PART_LIST="256,768"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/nx/defconfig b/nuttx/configs/mikroe-stm32f4/nx/defconfig
index d8d0b7906..be46deee5 100644
--- a/nuttx/configs/mikroe-stm32f4/nx/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/nx/defconfig
@@ -356,7 +356,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/nxlines/defconfig b/nuttx/configs/mikroe-stm32f4/nxlines/defconfig
index 312502876..d27d438ca 100644
--- a/nuttx/configs/mikroe-stm32f4/nxlines/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/nxlines/defconfig
@@ -356,7 +356,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/nxtext/defconfig b/nuttx/configs/mikroe-stm32f4/nxtext/defconfig
index ba73f2bef..85e5128a2 100644
--- a/nuttx/configs/mikroe-stm32f4/nxtext/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/nxtext/defconfig
@@ -356,7 +356,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mikroe-stm32f4/usbnsh/defconfig b/nuttx/configs/mikroe-stm32f4/usbnsh/defconfig
index 168e94fe9..cd412582f 100644
--- a/nuttx/configs/mikroe-stm32f4/usbnsh/defconfig
+++ b/nuttx/configs/mikroe-stm32f4/usbnsh/defconfig
@@ -379,7 +379,7 @@ CONFIG_MIKROE_RAMMTD_SIZE=32
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mirtoo/nsh/defconfig b/nuttx/configs/mirtoo/nsh/defconfig
index 8800630e7..6da9411c8 100644
--- a/nuttx/configs/mirtoo/nsh/defconfig
+++ b/nuttx/configs/mirtoo/nsh/defconfig
@@ -319,7 +319,7 @@ CONFIG_MIRTOO_RELEASE=2
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mirtoo/nxffs/defconfig b/nuttx/configs/mirtoo/nxffs/defconfig
index 43c8c03b8..d52a089e3 100644
--- a/nuttx/configs/mirtoo/nxffs/defconfig
+++ b/nuttx/configs/mirtoo/nxffs/defconfig
@@ -320,7 +320,7 @@ CONFIG_MIRTOO_RELEASE=2
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/mx1ads/ostest/defconfig b/nuttx/configs/mx1ads/ostest/defconfig
index 7ca9f08c5..dae941db8 100644
--- a/nuttx/configs/mx1ads/ostest/defconfig
+++ b/nuttx/configs/mx1ads/ostest/defconfig
@@ -185,7 +185,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ne64badge/ostest/defconfig b/nuttx/configs/ne64badge/ostest/defconfig
index ab58c80bf..a86b93597 100644
--- a/nuttx/configs/ne64badge/ostest/defconfig
+++ b/nuttx/configs/ne64badge/ostest/defconfig
@@ -164,7 +164,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ntosd-dm320/nettest/defconfig b/nuttx/configs/ntosd-dm320/nettest/defconfig
index 3c81781c0..047b3bc17 100644
--- a/nuttx/configs/ntosd-dm320/nettest/defconfig
+++ b/nuttx/configs/ntosd-dm320/nettest/defconfig
@@ -193,7 +193,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ntosd-dm320/nsh/defconfig b/nuttx/configs/ntosd-dm320/nsh/defconfig
index be2ce7adb..033d91939 100644
--- a/nuttx/configs/ntosd-dm320/nsh/defconfig
+++ b/nuttx/configs/ntosd-dm320/nsh/defconfig
@@ -195,7 +195,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ntosd-dm320/poll/defconfig b/nuttx/configs/ntosd-dm320/poll/defconfig
index a8c70280a..7e49df34b 100644
--- a/nuttx/configs/ntosd-dm320/poll/defconfig
+++ b/nuttx/configs/ntosd-dm320/poll/defconfig
@@ -193,7 +193,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ntosd-dm320/thttpd/defconfig b/nuttx/configs/ntosd-dm320/thttpd/defconfig
index c3b3c6c23..68113b2dc 100644
--- a/nuttx/configs/ntosd-dm320/thttpd/defconfig
+++ b/nuttx/configs/ntosd-dm320/thttpd/defconfig
@@ -193,7 +193,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ntosd-dm320/udp/defconfig b/nuttx/configs/ntosd-dm320/udp/defconfig
index 1f6ff379c..db542d35a 100644
--- a/nuttx/configs/ntosd-dm320/udp/defconfig
+++ b/nuttx/configs/ntosd-dm320/udp/defconfig
@@ -193,7 +193,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/ntosd-dm320/webserver/defconfig b/nuttx/configs/ntosd-dm320/webserver/defconfig
index c6a7ce245..3d911a018 100644
--- a/nuttx/configs/ntosd-dm320/webserver/defconfig
+++ b/nuttx/configs/ntosd-dm320/webserver/defconfig
@@ -193,7 +193,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/nucleo-f401re/nsh/defconfig b/nuttx/configs/nucleo-f401re/nsh/defconfig
index 6d679dec0..7c4222ed6 100644
--- a/nuttx/configs/nucleo-f401re/nsh/defconfig
+++ b/nuttx/configs/nucleo-f401re/nsh/defconfig
@@ -398,7 +398,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/nucleus2g/nsh/defconfig b/nuttx/configs/nucleus2g/nsh/defconfig
index b9dc30d80..54a770791 100644
--- a/nuttx/configs/nucleus2g/nsh/defconfig
+++ b/nuttx/configs/nucleus2g/nsh/defconfig
@@ -267,7 +267,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/nucleus2g/usbmsc/defconfig b/nuttx/configs/nucleus2g/usbmsc/defconfig
index 953297995..4d39ecf35 100644
--- a/nuttx/configs/nucleus2g/usbmsc/defconfig
+++ b/nuttx/configs/nucleus2g/usbmsc/defconfig
@@ -257,7 +257,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/nucleus2g/usbserial/defconfig b/nuttx/configs/nucleus2g/usbserial/defconfig
index b74c5b690..20b0d6894 100644
--- a/nuttx/configs/nucleus2g/usbserial/defconfig
+++ b/nuttx/configs/nucleus2g/usbserial/defconfig
@@ -238,7 +238,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/nutiny-nuc120/nsh/defconfig b/nuttx/configs/nutiny-nuc120/nsh/defconfig
index 1e3d45607..99b506760 100644
--- a/nuttx/configs/nutiny-nuc120/nsh/defconfig
+++ b/nuttx/configs/nutiny-nuc120/nsh/defconfig
@@ -231,7 +231,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/olimex-lpc-h3131/nsh/defconfig b/nuttx/configs/olimex-lpc-h3131/nsh/defconfig
index 896355a85..3b8ce6007 100644
--- a/nuttx/configs/olimex-lpc-h3131/nsh/defconfig
+++ b/nuttx/configs/olimex-lpc-h3131/nsh/defconfig
@@ -208,7 +208,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/olimex-lpc1766stk/ftpc/defconfig b/nuttx/configs/olimex-lpc1766stk/ftpc/defconfig
index 965ea8d46..48a8c4c93 100644
--- a/nuttx/configs/olimex-lpc1766stk/ftpc/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/ftpc/defconfig
@@ -284,7 +284,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/hidkbd/defconfig b/nuttx/configs/olimex-lpc1766stk/hidkbd/defconfig
index 99ac5877e..cbe513fb7 100644
--- a/nuttx/configs/olimex-lpc1766stk/hidkbd/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/hidkbd/defconfig
@@ -291,7 +291,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/hidmouse/defconfig b/nuttx/configs/olimex-lpc1766stk/hidmouse/defconfig
index 0b60ed060..c483b2961 100644
--- a/nuttx/configs/olimex-lpc1766stk/hidmouse/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/hidmouse/defconfig
@@ -293,7 +293,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/nettest/defconfig b/nuttx/configs/olimex-lpc1766stk/nettest/defconfig
index 7c70a3c5d..68d0a0077 100644
--- a/nuttx/configs/olimex-lpc1766stk/nettest/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/nettest/defconfig
@@ -282,7 +282,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/nsh/defconfig b/nuttx/configs/olimex-lpc1766stk/nsh/defconfig
index ab6ea6026..f559cff82 100644
--- a/nuttx/configs/olimex-lpc1766stk/nsh/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/nsh/defconfig
@@ -285,7 +285,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/nx/defconfig b/nuttx/configs/olimex-lpc1766stk/nx/defconfig
index d08960b7d..95692a276 100644
--- a/nuttx/configs/olimex-lpc1766stk/nx/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/nx/defconfig
@@ -279,7 +279,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig b/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig
index 69967e5f2..6f7015ed0 100644
--- a/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/slip-httpd/defconfig
@@ -273,7 +273,7 @@ CONFIG_DISABLE_MQUEUE=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/thttpd/defconfig b/nuttx/configs/olimex-lpc1766stk/thttpd/defconfig
index ca0fafaa9..525f65261 100644
--- a/nuttx/configs/olimex-lpc1766stk/thttpd/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/thttpd/defconfig
@@ -282,7 +282,7 @@ CONFIG_DISABLE_MQUEUE=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/usbmsc/defconfig b/nuttx/configs/olimex-lpc1766stk/usbmsc/defconfig
index 3f6ab42de..96838b404 100644
--- a/nuttx/configs/olimex-lpc1766stk/usbmsc/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/usbmsc/defconfig
@@ -282,7 +282,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/usbserial/defconfig b/nuttx/configs/olimex-lpc1766stk/usbserial/defconfig
index f459109a9..65305eaf5 100644
--- a/nuttx/configs/olimex-lpc1766stk/usbserial/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/usbserial/defconfig
@@ -282,7 +282,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc1766stk/zmodem/defconfig b/nuttx/configs/olimex-lpc1766stk/zmodem/defconfig
index 5f754f511..a5070f5e0 100644
--- a/nuttx/configs/olimex-lpc1766stk/zmodem/defconfig
+++ b/nuttx/configs/olimex-lpc1766stk/zmodem/defconfig
@@ -286,7 +286,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-lpc2378/nsh/defconfig b/nuttx/configs/olimex-lpc2378/nsh/defconfig
index f964b70ad..2509e5e13 100644
--- a/nuttx/configs/olimex-lpc2378/nsh/defconfig
+++ b/nuttx/configs/olimex-lpc2378/nsh/defconfig
@@ -199,7 +199,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/olimex-stm32-h405/nshusb/defconfig b/nuttx/configs/olimex-stm32-h405/nshusb/defconfig
index 96956cb7f..d24b05fcc 100644
--- a/nuttx/configs/olimex-stm32-h405/nshusb/defconfig
+++ b/nuttx/configs/olimex-stm32-h405/nshusb/defconfig
@@ -398,7 +398,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/olimex-stm32-p107/nsh/defconfig b/nuttx/configs/olimex-stm32-p107/nsh/defconfig
index 76931fd4f..45777d4e8 100644
--- a/nuttx/configs/olimex-stm32-p107/nsh/defconfig
+++ b/nuttx/configs/olimex-stm32-p107/nsh/defconfig
@@ -330,7 +330,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/olimex-stm32-p207/nsh/defconfig b/nuttx/configs/olimex-stm32-p207/nsh/defconfig
index 09adfb591..414d23455 100644
--- a/nuttx/configs/olimex-stm32-p207/nsh/defconfig
+++ b/nuttx/configs/olimex-stm32-p207/nsh/defconfig
@@ -381,7 +381,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/olimex-strp711/nettest/defconfig b/nuttx/configs/olimex-strp711/nettest/defconfig
index 90f81bbe1..1e674f102 100644
--- a/nuttx/configs/olimex-strp711/nettest/defconfig
+++ b/nuttx/configs/olimex-strp711/nettest/defconfig
@@ -218,7 +218,7 @@ CONFIG_ARCH_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/olimex-strp711/nsh/defconfig b/nuttx/configs/olimex-strp711/nsh/defconfig
index a80394dc5..9d9a25b47 100644
--- a/nuttx/configs/olimex-strp711/nsh/defconfig
+++ b/nuttx/configs/olimex-strp711/nsh/defconfig
@@ -221,7 +221,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=1
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/open1788/knsh/defconfig b/nuttx/configs/open1788/knsh/defconfig
index 12c8b37fd..77b319aa8 100644
--- a/nuttx/configs/open1788/knsh/defconfig
+++ b/nuttx/configs/open1788/knsh/defconfig
@@ -284,7 +284,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/open1788/nsh/defconfig b/nuttx/configs/open1788/nsh/defconfig
index 216453c3d..deb3e2be3 100644
--- a/nuttx/configs/open1788/nsh/defconfig
+++ b/nuttx/configs/open1788/nsh/defconfig
@@ -241,7 +241,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/open1788/nxlines/defconfig b/nuttx/configs/open1788/nxlines/defconfig
index 1707a7c27..2b768bd0c 100644
--- a/nuttx/configs/open1788/nxlines/defconfig
+++ b/nuttx/configs/open1788/nxlines/defconfig
@@ -274,7 +274,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/p112/ostest/defconfig b/nuttx/configs/p112/ostest/defconfig
index 23e5ef5e0..10e876fb2 100644
--- a/nuttx/configs/p112/ostest/defconfig
+++ b/nuttx/configs/p112/ostest/defconfig
@@ -200,7 +200,7 @@ CONFIG_ARCH_BOARD="p112"
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/pcblogic-pic32mx/nsh/defconfig b/nuttx/configs/pcblogic-pic32mx/nsh/defconfig
index bdd782026..a1ad66b60 100644
--- a/nuttx/configs/pcblogic-pic32mx/nsh/defconfig
+++ b/nuttx/configs/pcblogic-pic32mx/nsh/defconfig
@@ -294,7 +294,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/pcduino-a10/nsh/defconfig b/nuttx/configs/pcduino-a10/nsh/defconfig
index a647d4729..3ab55c464 100644
--- a/nuttx/configs/pcduino-a10/nsh/defconfig
+++ b/nuttx/configs/pcduino-a10/nsh/defconfig
@@ -262,7 +262,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/pic32-starterkit/nsh/defconfig b/nuttx/configs/pic32-starterkit/nsh/defconfig
index 2fe0e5468..d4a20b5ec 100644
--- a/nuttx/configs/pic32-starterkit/nsh/defconfig
+++ b/nuttx/configs/pic32-starterkit/nsh/defconfig
@@ -321,7 +321,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/pic32-starterkit/nsh2/defconfig b/nuttx/configs/pic32-starterkit/nsh2/defconfig
index 077362ac3..c0f93839c 100644
--- a/nuttx/configs/pic32-starterkit/nsh2/defconfig
+++ b/nuttx/configs/pic32-starterkit/nsh2/defconfig
@@ -330,7 +330,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/pic32mx7mmb/nsh/defconfig b/nuttx/configs/pic32mx7mmb/nsh/defconfig
index 3ae17449a..308ede122 100644
--- a/nuttx/configs/pic32mx7mmb/nsh/defconfig
+++ b/nuttx/configs/pic32mx7mmb/nsh/defconfig
@@ -336,7 +336,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=1
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/pirelli_dpl10/nsh_highram/defconfig b/nuttx/configs/pirelli_dpl10/nsh_highram/defconfig
index bc4d31edf..acdadc2da 100644
--- a/nuttx/configs/pirelli_dpl10/nsh_highram/defconfig
+++ b/nuttx/configs/pirelli_dpl10/nsh_highram/defconfig
@@ -180,7 +180,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/pjrc-8051/defconfig b/nuttx/configs/pjrc-8051/defconfig
index f508af256..53eb77ec9 100644
--- a/nuttx/configs/pjrc-8051/defconfig
+++ b/nuttx/configs/pjrc-8051/defconfig
@@ -142,7 +142,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/px4fmu-v2_upstream/nsh/defconfig b/nuttx/configs/px4fmu-v2_upstream/nsh/defconfig
index 9343d3513..7b08d4163 100644
--- a/nuttx/configs/px4fmu-v2_upstream/nsh/defconfig
+++ b/nuttx/configs/px4fmu-v2_upstream/nsh/defconfig
@@ -418,7 +418,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/qemu-i486/nsh/defconfig b/nuttx/configs/qemu-i486/nsh/defconfig
index f6c7d8f45..29a0af36f 100644
--- a/nuttx/configs/qemu-i486/nsh/defconfig
+++ b/nuttx/configs/qemu-i486/nsh/defconfig
@@ -152,7 +152,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/qemu-i486/ostest/defconfig b/nuttx/configs/qemu-i486/ostest/defconfig
index a2282f78b..39e79498d 100644
--- a/nuttx/configs/qemu-i486/ostest/defconfig
+++ b/nuttx/configs/qemu-i486/ostest/defconfig
@@ -151,7 +151,7 @@ CONFIG_ARCH_BOARD="qemu-i486"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/rgmp/arm/default/defconfig b/nuttx/configs/rgmp/arm/default/defconfig
index 548fb648c..527e48b5e 100644
--- a/nuttx/configs/rgmp/arm/default/defconfig
+++ b/nuttx/configs/rgmp/arm/default/defconfig
@@ -136,7 +136,7 @@ CONFIG_ARCH_BOARD="rgmp"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/rgmp/arm/nsh/defconfig b/nuttx/configs/rgmp/arm/nsh/defconfig
index b6c6d3044..f220399da 100644
--- a/nuttx/configs/rgmp/arm/nsh/defconfig
+++ b/nuttx/configs/rgmp/arm/nsh/defconfig
@@ -157,7 +157,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/rgmp/x86/cxxtest/defconfig b/nuttx/configs/rgmp/x86/cxxtest/defconfig
index 71a4284c5..f6b08e92f 100644
--- a/nuttx/configs/rgmp/x86/cxxtest/defconfig
+++ b/nuttx/configs/rgmp/x86/cxxtest/defconfig
@@ -164,7 +164,7 @@ CONFIG_ARCH_BOARD="rgmp"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/rgmp/x86/default/defconfig b/nuttx/configs/rgmp/x86/default/defconfig
index 60c5edec2..faa7c64d5 100644
--- a/nuttx/configs/rgmp/x86/default/defconfig
+++ b/nuttx/configs/rgmp/x86/default/defconfig
@@ -144,7 +144,7 @@ CONFIG_ARCH_BOARD="rgmp"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/rgmp/x86/helloxx/defconfig b/nuttx/configs/rgmp/x86/helloxx/defconfig
index ad45dbeb6..1feb05a4d 100644
--- a/nuttx/configs/rgmp/x86/helloxx/defconfig
+++ b/nuttx/configs/rgmp/x86/helloxx/defconfig
@@ -164,7 +164,7 @@ CONFIG_ARCH_BOARD="rgmp"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/rgmp/x86/nsh/defconfig b/nuttx/configs/rgmp/x86/nsh/defconfig
index 729c97c5c..02297f551 100644
--- a/nuttx/configs/rgmp/x86/nsh/defconfig
+++ b/nuttx/configs/rgmp/x86/nsh/defconfig
@@ -165,7 +165,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=1
+CONFIG_USEC_PER_TICK=1000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam3u-ek/knsh/defconfig b/nuttx/configs/sam3u-ek/knsh/defconfig
index b681d09a9..542ae7677 100644
--- a/nuttx/configs/sam3u-ek/knsh/defconfig
+++ b/nuttx/configs/sam3u-ek/knsh/defconfig
@@ -289,7 +289,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam3u-ek/nsh/defconfig b/nuttx/configs/sam3u-ek/nsh/defconfig
index c6cb8509d..cce7bab5c 100644
--- a/nuttx/configs/sam3u-ek/nsh/defconfig
+++ b/nuttx/configs/sam3u-ek/nsh/defconfig
@@ -282,7 +282,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam3u-ek/nx/defconfig b/nuttx/configs/sam3u-ek/nx/defconfig
index 7525bf8c2..80a9bab4a 100644
--- a/nuttx/configs/sam3u-ek/nx/defconfig
+++ b/nuttx/configs/sam3u-ek/nx/defconfig
@@ -281,7 +281,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam3u-ek/nxwm/defconfig b/nuttx/configs/sam3u-ek/nxwm/defconfig
index 18d6b9fdd..c6ceba2b9 100644
--- a/nuttx/configs/sam3u-ek/nxwm/defconfig
+++ b/nuttx/configs/sam3u-ek/nxwm/defconfig
@@ -285,7 +285,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam4e-ek/nsh/defconfig b/nuttx/configs/sam4e-ek/nsh/defconfig
index b232ddc1e..8107b6c4e 100644
--- a/nuttx/configs/sam4e-ek/nsh/defconfig
+++ b/nuttx/configs/sam4e-ek/nsh/defconfig
@@ -338,7 +338,7 @@ CONFIG_SAM4EEK_AT25_FTL=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam4e-ek/usbnsh/defconfig b/nuttx/configs/sam4e-ek/usbnsh/defconfig
index 83d2a4093..dad34d1cb 100644
--- a/nuttx/configs/sam4e-ek/usbnsh/defconfig
+++ b/nuttx/configs/sam4e-ek/usbnsh/defconfig
@@ -343,7 +343,7 @@ CONFIG_SAM4EEK_AT25_FTL=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam4l-xplained/nsh/defconfig b/nuttx/configs/sam4l-xplained/nsh/defconfig
index fc955a3d9..0388b6b69 100644
--- a/nuttx/configs/sam4l-xplained/nsh/defconfig
+++ b/nuttx/configs/sam4l-xplained/nsh/defconfig
@@ -305,7 +305,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sam4s-xplained-pro/nsh/defconfig b/nuttx/configs/sam4s-xplained-pro/nsh/defconfig
index b8e7bfeb7..37a027964 100644
--- a/nuttx/configs/sam4s-xplained-pro/nsh/defconfig
+++ b/nuttx/configs/sam4s-xplained-pro/nsh/defconfig
@@ -335,7 +335,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_SYSTEMTICK_EXTCLK=y
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
diff --git a/nuttx/configs/sam4s-xplained/nsh/defconfig b/nuttx/configs/sam4s-xplained/nsh/defconfig
index 052e79830..39449c9b7 100644
--- a/nuttx/configs/sam4s-xplained/nsh/defconfig
+++ b/nuttx/configs/sam4s-xplained/nsh/defconfig
@@ -284,7 +284,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sama5d3-xplained/nsh/defconfig b/nuttx/configs/sama5d3-xplained/nsh/defconfig
index 2927a45a9..443f6a36a 100644
--- a/nuttx/configs/sama5d3-xplained/nsh/defconfig
+++ b/nuttx/configs/sama5d3-xplained/nsh/defconfig
@@ -319,7 +319,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/demo/defconfig b/nuttx/configs/sama5d3x-ek/demo/defconfig
index cb2b61b6c..7c4e8e5ee 100644
--- a/nuttx/configs/sama5d3x-ek/demo/defconfig
+++ b/nuttx/configs/sama5d3x-ek/demo/defconfig
@@ -376,7 +376,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/hello/defconfig b/nuttx/configs/sama5d3x-ek/hello/defconfig
index b6717f8d3..3a19a4848 100644
--- a/nuttx/configs/sama5d3x-ek/hello/defconfig
+++ b/nuttx/configs/sama5d3x-ek/hello/defconfig
@@ -300,7 +300,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/norboot/defconfig b/nuttx/configs/sama5d3x-ek/norboot/defconfig
index b75968ae9..7566d31b0 100644
--- a/nuttx/configs/sama5d3x-ek/norboot/defconfig
+++ b/nuttx/configs/sama5d3x-ek/norboot/defconfig
@@ -314,7 +314,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/nsh/defconfig b/nuttx/configs/sama5d3x-ek/nsh/defconfig
index a61b3ff83..73b6657b6 100644
--- a/nuttx/configs/sama5d3x-ek/nsh/defconfig
+++ b/nuttx/configs/sama5d3x-ek/nsh/defconfig
@@ -322,7 +322,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/nx/defconfig b/nuttx/configs/sama5d3x-ek/nx/defconfig
index f1def5693..fd64b7c74 100644
--- a/nuttx/configs/sama5d3x-ek/nx/defconfig
+++ b/nuttx/configs/sama5d3x-ek/nx/defconfig
@@ -359,7 +359,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/nxplayer/defconfig b/nuttx/configs/sama5d3x-ek/nxplayer/defconfig
index be017823e..9a4682fb2 100644
--- a/nuttx/configs/sama5d3x-ek/nxplayer/defconfig
+++ b/nuttx/configs/sama5d3x-ek/nxplayer/defconfig
@@ -381,7 +381,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/nxwm/defconfig b/nuttx/configs/sama5d3x-ek/nxwm/defconfig
index 86cab4175..63d329e1c 100644
--- a/nuttx/configs/sama5d3x-ek/nxwm/defconfig
+++ b/nuttx/configs/sama5d3x-ek/nxwm/defconfig
@@ -392,7 +392,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d3x-ek/ov2640/defconfig b/nuttx/configs/sama5d3x-ek/ov2640/defconfig
index 60906f60f..3b63df733 100644
--- a/nuttx/configs/sama5d3x-ek/ov2640/defconfig
+++ b/nuttx/configs/sama5d3x-ek/ov2640/defconfig
@@ -365,7 +365,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d4-ek/at25boot/defconfig b/nuttx/configs/sama5d4-ek/at25boot/defconfig
index 97d01cb46..bd4ed89ed 100644
--- a/nuttx/configs/sama5d4-ek/at25boot/defconfig
+++ b/nuttx/configs/sama5d4-ek/at25boot/defconfig
@@ -339,7 +339,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d4-ek/dramboot/defconfig b/nuttx/configs/sama5d4-ek/dramboot/defconfig
index 66b6a8e0b..b1b16d76c 100644
--- a/nuttx/configs/sama5d4-ek/dramboot/defconfig
+++ b/nuttx/configs/sama5d4-ek/dramboot/defconfig
@@ -337,7 +337,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d4-ek/nsh/defconfig b/nuttx/configs/sama5d4-ek/nsh/defconfig
index 1ce6544a0..da666e27d 100644
--- a/nuttx/configs/sama5d4-ek/nsh/defconfig
+++ b/nuttx/configs/sama5d4-ek/nsh/defconfig
@@ -439,7 +439,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d4-ek/nxwm/defconfig b/nuttx/configs/sama5d4-ek/nxwm/defconfig
index ae2f2d60b..dd65b2b1f 100644
--- a/nuttx/configs/sama5d4-ek/nxwm/defconfig
+++ b/nuttx/configs/sama5d4-ek/nxwm/defconfig
@@ -439,7 +439,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sama5d4-ek/ramtest/defconfig b/nuttx/configs/sama5d4-ek/ramtest/defconfig
index 3db1a7752..0769c9e62 100644
--- a/nuttx/configs/sama5d4-ek/ramtest/defconfig
+++ b/nuttx/configs/sama5d4-ek/ramtest/defconfig
@@ -330,7 +330,7 @@ CONFIG_DISABLE_ENVIRON=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/samd20-xplained/nsh/defconfig b/nuttx/configs/samd20-xplained/nsh/defconfig
index 2813633fc..6993f9f54 100644
--- a/nuttx/configs/samd20-xplained/nsh/defconfig
+++ b/nuttx/configs/samd20-xplained/nsh/defconfig
@@ -258,7 +258,7 @@ CONFIG_SAMD20_XPLAINED_USART4_EXT3=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/shenzhou/nsh/defconfig b/nuttx/configs/shenzhou/nsh/defconfig
index 59985071d..759b02aa6 100644
--- a/nuttx/configs/shenzhou/nsh/defconfig
+++ b/nuttx/configs/shenzhou/nsh/defconfig
@@ -253,7 +253,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=1
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/shenzhou/nxwm/defconfig b/nuttx/configs/shenzhou/nxwm/defconfig
index 24eafa29e..31d3a2c53 100644
--- a/nuttx/configs/shenzhou/nxwm/defconfig
+++ b/nuttx/configs/shenzhou/nxwm/defconfig
@@ -393,7 +393,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/shenzhou/thttpd/defconfig b/nuttx/configs/shenzhou/thttpd/defconfig
index a574cd1c7..9a0067d80 100644
--- a/nuttx/configs/shenzhou/thttpd/defconfig
+++ b/nuttx/configs/shenzhou/thttpd/defconfig
@@ -240,7 +240,7 @@ CONFIG_NSH_MMCSDSPIPORTNO=1
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/sim/configdata/defconfig b/nuttx/configs/sim/configdata/defconfig
index 142ea9c16..cbe17891d 100644
--- a/nuttx/configs/sim/configdata/defconfig
+++ b/nuttx/configs/sim/configdata/defconfig
@@ -153,7 +153,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/cxxtest/defconfig b/nuttx/configs/sim/cxxtest/defconfig
index 2672e1ac7..c0ff11bf4 100644
--- a/nuttx/configs/sim/cxxtest/defconfig
+++ b/nuttx/configs/sim/cxxtest/defconfig
@@ -153,7 +153,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/mount/defconfig b/nuttx/configs/sim/mount/defconfig
index 9b4662699..da11fa3c1 100644
--- a/nuttx/configs/sim/mount/defconfig
+++ b/nuttx/configs/sim/mount/defconfig
@@ -153,7 +153,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/mtdpart/defconfig b/nuttx/configs/sim/mtdpart/defconfig
index c5036f665..ab841a91b 100644
--- a/nuttx/configs/sim/mtdpart/defconfig
+++ b/nuttx/configs/sim/mtdpart/defconfig
@@ -153,7 +153,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/nettest/defconfig b/nuttx/configs/sim/nettest/defconfig
index 09ccf3843..4911cac57 100755
--- a/nuttx/configs/sim/nettest/defconfig
+++ b/nuttx/configs/sim/nettest/defconfig
@@ -146,7 +146,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sim/nsh/defconfig b/nuttx/configs/sim/nsh/defconfig
index 8a8d1b00e..e2ee4e6fb 100644
--- a/nuttx/configs/sim/nsh/defconfig
+++ b/nuttx/configs/sim/nsh/defconfig
@@ -146,7 +146,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sim/nsh2/defconfig b/nuttx/configs/sim/nsh2/defconfig
index 435653aaf..91fe81100 100644
--- a/nuttx/configs/sim/nsh2/defconfig
+++ b/nuttx/configs/sim/nsh2/defconfig
@@ -141,7 +141,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/nx/defconfig b/nuttx/configs/sim/nx/defconfig
index dd4250e92..c320668e1 100644
--- a/nuttx/configs/sim/nx/defconfig
+++ b/nuttx/configs/sim/nx/defconfig
@@ -158,7 +158,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/nx11/defconfig b/nuttx/configs/sim/nx11/defconfig
index 0cc3ab799..ee727df1b 100644
--- a/nuttx/configs/sim/nx11/defconfig
+++ b/nuttx/configs/sim/nx11/defconfig
@@ -159,7 +159,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/nxffs/defconfig b/nuttx/configs/sim/nxffs/defconfig
index a833eed40..d14598ed8 100644
--- a/nuttx/configs/sim/nxffs/defconfig
+++ b/nuttx/configs/sim/nxffs/defconfig
@@ -134,7 +134,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/nxlines/defconfig b/nuttx/configs/sim/nxlines/defconfig
index 64828d3e7..d7aaf0841 100644
--- a/nuttx/configs/sim/nxlines/defconfig
+++ b/nuttx/configs/sim/nxlines/defconfig
@@ -145,7 +145,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/nxwm/defconfig b/nuttx/configs/sim/nxwm/defconfig
index eafc479c8..d13da3e75 100644
--- a/nuttx/configs/sim/nxwm/defconfig
+++ b/nuttx/configs/sim/nxwm/defconfig
@@ -141,7 +141,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/ostest/defconfig b/nuttx/configs/sim/ostest/defconfig
index fdcc46589..51ac6cd58 100644
--- a/nuttx/configs/sim/ostest/defconfig
+++ b/nuttx/configs/sim/ostest/defconfig
@@ -153,7 +153,7 @@ CONFIG_ARCH_BOARD="sim"
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/sim/pashello/defconfig b/nuttx/configs/sim/pashello/defconfig
index c32a96920..3dbeea5eb 100644
--- a/nuttx/configs/sim/pashello/defconfig
+++ b/nuttx/configs/sim/pashello/defconfig
@@ -145,7 +145,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/sim/touchscreen/defconfig b/nuttx/configs/sim/touchscreen/defconfig
index 2b55275d1..223c545fd 100644
--- a/nuttx/configs/sim/touchscreen/defconfig
+++ b/nuttx/configs/sim/touchscreen/defconfig
@@ -163,7 +163,7 @@ CONFIG_EXAMPLES_TOUCHSCREEN_BGCOLOR=0x007b68ee
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/skp16c26/ostest/defconfig b/nuttx/configs/skp16c26/ostest/defconfig
index e7cd32cdf..69950f097 100644
--- a/nuttx/configs/skp16c26/ostest/defconfig
+++ b/nuttx/configs/skp16c26/ostest/defconfig
@@ -139,7 +139,7 @@ CONFIG_ARCH_HAVE_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/spark/composite/defconfig b/nuttx/configs/spark/composite/defconfig
index 7e89c6877..37649e079 100644
--- a/nuttx/configs/spark/composite/defconfig
+++ b/nuttx/configs/spark/composite/defconfig
@@ -362,7 +362,7 @@ CONFIG_SPARK_FLASH_MINOR=0
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/spark/nsh/defconfig b/nuttx/configs/spark/nsh/defconfig
index d0bdb8c3a..f18bf6b06 100644
--- a/nuttx/configs/spark/nsh/defconfig
+++ b/nuttx/configs/spark/nsh/defconfig
@@ -362,7 +362,7 @@ CONFIG_SPARK_FLASH_MINOR=0
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/spark/usbmsc/defconfig b/nuttx/configs/spark/usbmsc/defconfig
index 944a4a120..a202f9495 100644
--- a/nuttx/configs/spark/usbmsc/defconfig
+++ b/nuttx/configs/spark/usbmsc/defconfig
@@ -362,7 +362,7 @@ CONFIG_SPARK_FLASH_MINOR=0
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/spark/usbnsh/defconfig b/nuttx/configs/spark/usbnsh/defconfig
index 68a2f3fc1..7a8134445 100644
--- a/nuttx/configs/spark/usbnsh/defconfig
+++ b/nuttx/configs/spark/usbnsh/defconfig
@@ -361,7 +361,7 @@ CONFIG_SPARK_FLASH_MINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/spark/usbserial/defconfig b/nuttx/configs/spark/usbserial/defconfig
index cf021438b..2634d58c1 100644
--- a/nuttx/configs/spark/usbserial/defconfig
+++ b/nuttx/configs/spark/usbserial/defconfig
@@ -361,7 +361,7 @@ CONFIG_SPARK_FLASH_MINOR=0
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/buttons/defconfig b/nuttx/configs/stm3210e-eval/buttons/defconfig
index 901b34438..eca594217 100644
--- a/nuttx/configs/stm3210e-eval/buttons/defconfig
+++ b/nuttx/configs/stm3210e-eval/buttons/defconfig
@@ -364,7 +364,7 @@ CONFIG_ARCH_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/composite/defconfig b/nuttx/configs/stm3210e-eval/composite/defconfig
index e9ba6c79c..dc8eb9e69 100644
--- a/nuttx/configs/stm3210e-eval/composite/defconfig
+++ b/nuttx/configs/stm3210e-eval/composite/defconfig
@@ -372,7 +372,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/nsh/defconfig b/nuttx/configs/stm3210e-eval/nsh/defconfig
index f879621dc..5dcf5ad6d 100644
--- a/nuttx/configs/stm3210e-eval/nsh/defconfig
+++ b/nuttx/configs/stm3210e-eval/nsh/defconfig
@@ -375,7 +375,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/nsh2/defconfig b/nuttx/configs/stm3210e-eval/nsh2/defconfig
index ef6d9e88b..56a55ec52 100644
--- a/nuttx/configs/stm3210e-eval/nsh2/defconfig
+++ b/nuttx/configs/stm3210e-eval/nsh2/defconfig
@@ -390,7 +390,7 @@ CONFIG_STM3210E_R61580_DISABLE=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/nx/defconfig b/nuttx/configs/stm3210e-eval/nx/defconfig
index e5193dad2..b95bb12f0 100644
--- a/nuttx/configs/stm3210e-eval/nx/defconfig
+++ b/nuttx/configs/stm3210e-eval/nx/defconfig
@@ -380,7 +380,7 @@ CONFIG_STM3210E_R61580_DISABLE=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/nxconsole/defconfig b/nuttx/configs/stm3210e-eval/nxconsole/defconfig
index ff947f962..982c27cf2 100644
--- a/nuttx/configs/stm3210e-eval/nxconsole/defconfig
+++ b/nuttx/configs/stm3210e-eval/nxconsole/defconfig
@@ -370,7 +370,7 @@ CONFIG_STM3210E_R61580_DISABLE=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/pm/defconfig b/nuttx/configs/stm3210e-eval/pm/defconfig
index a3b02be5c..9404d573e 100644
--- a/nuttx/configs/stm3210e-eval/pm/defconfig
+++ b/nuttx/configs/stm3210e-eval/pm/defconfig
@@ -387,7 +387,7 @@ CONFIG_PM_BUTTON_ACTIVITY=10
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/usbmsc/defconfig b/nuttx/configs/stm3210e-eval/usbmsc/defconfig
index aa4cb26a8..958d9aadb 100644
--- a/nuttx/configs/stm3210e-eval/usbmsc/defconfig
+++ b/nuttx/configs/stm3210e-eval/usbmsc/defconfig
@@ -365,7 +365,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3210e-eval/usbserial/defconfig b/nuttx/configs/stm3210e-eval/usbserial/defconfig
index 598e7f3c1..c89f15cb0 100644
--- a/nuttx/configs/stm3210e-eval/usbserial/defconfig
+++ b/nuttx/configs/stm3210e-eval/usbserial/defconfig
@@ -356,7 +356,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3220g-eval/dhcpd/defconfig b/nuttx/configs/stm3220g-eval/dhcpd/defconfig
index a58a11c95..3d9b4a2b7 100644
--- a/nuttx/configs/stm3220g-eval/dhcpd/defconfig
+++ b/nuttx/configs/stm3220g-eval/dhcpd/defconfig
@@ -391,7 +391,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3220g-eval/nettest/defconfig b/nuttx/configs/stm3220g-eval/nettest/defconfig
index 822c11f27..ce92a4e32 100644
--- a/nuttx/configs/stm3220g-eval/nettest/defconfig
+++ b/nuttx/configs/stm3220g-eval/nettest/defconfig
@@ -391,7 +391,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3220g-eval/nsh/defconfig b/nuttx/configs/stm3220g-eval/nsh/defconfig
index 4ef7143ef..aa1f0ebbc 100644
--- a/nuttx/configs/stm3220g-eval/nsh/defconfig
+++ b/nuttx/configs/stm3220g-eval/nsh/defconfig
@@ -395,7 +395,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3220g-eval/nsh2/defconfig b/nuttx/configs/stm3220g-eval/nsh2/defconfig
index eea45f74f..e65c18fcf 100644
--- a/nuttx/configs/stm3220g-eval/nsh2/defconfig
+++ b/nuttx/configs/stm3220g-eval/nsh2/defconfig
@@ -403,7 +403,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3220g-eval/nxwm/defconfig b/nuttx/configs/stm3220g-eval/nxwm/defconfig
index 1d52a7e1e..cef46d0b3 100644
--- a/nuttx/configs/stm3220g-eval/nxwm/defconfig
+++ b/nuttx/configs/stm3220g-eval/nxwm/defconfig
@@ -408,7 +408,7 @@ CONFIG_LCD_RDSHIFT=5
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3220g-eval/telnetd/defconfig b/nuttx/configs/stm3220g-eval/telnetd/defconfig
index 0294aa40b..4160786fc 100644
--- a/nuttx/configs/stm3220g-eval/telnetd/defconfig
+++ b/nuttx/configs/stm3220g-eval/telnetd/defconfig
@@ -391,7 +391,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/dhcpd/defconfig b/nuttx/configs/stm3240g-eval/dhcpd/defconfig
index 2d7e3c9d5..f736ebd7a 100644
--- a/nuttx/configs/stm3240g-eval/dhcpd/defconfig
+++ b/nuttx/configs/stm3240g-eval/dhcpd/defconfig
@@ -393,7 +393,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/discover/defconfig b/nuttx/configs/stm3240g-eval/discover/defconfig
index a681e0228..11a46a2db 100644
--- a/nuttx/configs/stm3240g-eval/discover/defconfig
+++ b/nuttx/configs/stm3240g-eval/discover/defconfig
@@ -421,7 +421,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/knxwm/defconfig b/nuttx/configs/stm3240g-eval/knxwm/defconfig
index 92506b2dd..8a8e270e7 100644
--- a/nuttx/configs/stm3240g-eval/knxwm/defconfig
+++ b/nuttx/configs/stm3240g-eval/knxwm/defconfig
@@ -398,7 +398,7 @@ CONFIG_STM3240G_BOARDINIT_STACK=2048
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/nettest/defconfig b/nuttx/configs/stm3240g-eval/nettest/defconfig
index 60c139600..31b301ed5 100644
--- a/nuttx/configs/stm3240g-eval/nettest/defconfig
+++ b/nuttx/configs/stm3240g-eval/nettest/defconfig
@@ -393,7 +393,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/nsh/defconfig b/nuttx/configs/stm3240g-eval/nsh/defconfig
index ccf3feba0..dd231a9d8 100644
--- a/nuttx/configs/stm3240g-eval/nsh/defconfig
+++ b/nuttx/configs/stm3240g-eval/nsh/defconfig
@@ -404,7 +404,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/nsh2/defconfig b/nuttx/configs/stm3240g-eval/nsh2/defconfig
index 743855c3f..8e6548d65 100644
--- a/nuttx/configs/stm3240g-eval/nsh2/defconfig
+++ b/nuttx/configs/stm3240g-eval/nsh2/defconfig
@@ -405,7 +405,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/nxconsole/defconfig b/nuttx/configs/stm3240g-eval/nxconsole/defconfig
index 17c28b83e..330368dbc 100644
--- a/nuttx/configs/stm3240g-eval/nxconsole/defconfig
+++ b/nuttx/configs/stm3240g-eval/nxconsole/defconfig
@@ -409,7 +409,7 @@ CONFIG_STM3240G_LCD_RDSHIFT=5
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/nxwm/defconfig b/nuttx/configs/stm3240g-eval/nxwm/defconfig
index a7632e18d..d271b8158 100644
--- a/nuttx/configs/stm3240g-eval/nxwm/defconfig
+++ b/nuttx/configs/stm3240g-eval/nxwm/defconfig
@@ -409,7 +409,7 @@ CONFIG_STM3240G_LCD_RDSHIFT=5
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/telnetd/defconfig b/nuttx/configs/stm3240g-eval/telnetd/defconfig
index 3141d9d98..f03c3cafc 100644
--- a/nuttx/configs/stm3240g-eval/telnetd/defconfig
+++ b/nuttx/configs/stm3240g-eval/telnetd/defconfig
@@ -393,7 +393,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/webserver/defconfig b/nuttx/configs/stm3240g-eval/webserver/defconfig
index 7880c3f3e..6dfd23ab7 100644
--- a/nuttx/configs/stm3240g-eval/webserver/defconfig
+++ b/nuttx/configs/stm3240g-eval/webserver/defconfig
@@ -396,7 +396,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm3240g-eval/xmlrpc/defconfig b/nuttx/configs/stm3240g-eval/xmlrpc/defconfig
index 0483a42af..931a1fb0a 100644
--- a/nuttx/configs/stm3240g-eval/xmlrpc/defconfig
+++ b/nuttx/configs/stm3240g-eval/xmlrpc/defconfig
@@ -421,7 +421,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32_tiny/nsh/defconfig b/nuttx/configs/stm32_tiny/nsh/defconfig
index 6e768e4e4..d355c5d08 100644
--- a/nuttx/configs/stm32_tiny/nsh/defconfig
+++ b/nuttx/configs/stm32_tiny/nsh/defconfig
@@ -306,7 +306,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32_tiny/usbnsh/defconfig b/nuttx/configs/stm32_tiny/usbnsh/defconfig
index c425e91fc..0ea2b96e2 100644
--- a/nuttx/configs/stm32_tiny/usbnsh/defconfig
+++ b/nuttx/configs/stm32_tiny/usbnsh/defconfig
@@ -270,7 +270,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32f100rc_generic/nsh/defconfig b/nuttx/configs/stm32f100rc_generic/nsh/defconfig
index 16a846286..ea16e41c6 100644
--- a/nuttx/configs/stm32f100rc_generic/nsh/defconfig
+++ b/nuttx/configs/stm32f100rc_generic/nsh/defconfig
@@ -230,7 +230,7 @@ CONFIG_NSH_MMCSDMINOR=0
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32f3discovery/nsh/defconfig b/nuttx/configs/stm32f3discovery/nsh/defconfig
index 472664380..e97b7d4df 100644
--- a/nuttx/configs/stm32f3discovery/nsh/defconfig
+++ b/nuttx/configs/stm32f3discovery/nsh/defconfig
@@ -324,7 +324,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32f3discovery/usbnsh/defconfig b/nuttx/configs/stm32f3discovery/usbnsh/defconfig
index a6d9ea1f3..27a9a161f 100644
--- a/nuttx/configs/stm32f3discovery/usbnsh/defconfig
+++ b/nuttx/configs/stm32f3discovery/usbnsh/defconfig
@@ -316,7 +316,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32f429i-disco/extflash/defconfig b/nuttx/configs/stm32f429i-disco/extflash/defconfig
index 01c5b1f2d..6fffcf6de 100644
--- a/nuttx/configs/stm32f429i-disco/extflash/defconfig
+++ b/nuttx/configs/stm32f429i-disco/extflash/defconfig
@@ -417,7 +417,7 @@ CONFIG_STM32F429I_DISCO_RAMMTD_SIZE=256
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f429i-disco/nsh/defconfig b/nuttx/configs/stm32f429i-disco/nsh/defconfig
index c266e0d65..bd9adf2c5 100644
--- a/nuttx/configs/stm32f429i-disco/nsh/defconfig
+++ b/nuttx/configs/stm32f429i-disco/nsh/defconfig
@@ -402,7 +402,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f429i-disco/usbmsc/defconfig b/nuttx/configs/stm32f429i-disco/usbmsc/defconfig
index a192adfb3..1fa30cc00 100644
--- a/nuttx/configs/stm32f429i-disco/usbmsc/defconfig
+++ b/nuttx/configs/stm32f429i-disco/usbmsc/defconfig
@@ -415,7 +415,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f429i-disco/usbnsh/defconfig b/nuttx/configs/stm32f429i-disco/usbnsh/defconfig
index 2b8cd9679..58b6ccaa3 100644
--- a/nuttx/configs/stm32f429i-disco/usbnsh/defconfig
+++ b/nuttx/configs/stm32f429i-disco/usbnsh/defconfig
@@ -412,7 +412,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/cxxtest/defconfig b/nuttx/configs/stm32f4discovery/cxxtest/defconfig
index ef8788562..044452a03 100644
--- a/nuttx/configs/stm32f4discovery/cxxtest/defconfig
+++ b/nuttx/configs/stm32f4discovery/cxxtest/defconfig
@@ -375,7 +375,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/elf/defconfig b/nuttx/configs/stm32f4discovery/elf/defconfig
index 58d81d0d9..14ca07060 100644
--- a/nuttx/configs/stm32f4discovery/elf/defconfig
+++ b/nuttx/configs/stm32f4discovery/elf/defconfig
@@ -375,7 +375,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/kostest/defconfig b/nuttx/configs/stm32f4discovery/kostest/defconfig
index 8f60d6500..c6335b1f9 100644
--- a/nuttx/configs/stm32f4discovery/kostest/defconfig
+++ b/nuttx/configs/stm32f4discovery/kostest/defconfig
@@ -381,7 +381,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 CONFIG_BOARD_INITIALIZE=y
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/nsh/defconfig b/nuttx/configs/stm32f4discovery/nsh/defconfig
index 4cd358e2b..b3ca47a26 100644
--- a/nuttx/configs/stm32f4discovery/nsh/defconfig
+++ b/nuttx/configs/stm32f4discovery/nsh/defconfig
@@ -384,7 +384,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/nxlines/defconfig b/nuttx/configs/stm32f4discovery/nxlines/defconfig
index 21e5cba0c..01df5ed62 100644
--- a/nuttx/configs/stm32f4discovery/nxlines/defconfig
+++ b/nuttx/configs/stm32f4discovery/nxlines/defconfig
@@ -385,7 +385,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/pm/defconfig b/nuttx/configs/stm32f4discovery/pm/defconfig
index 8fafc0d03..cbb2efeaa 100644
--- a/nuttx/configs/stm32f4discovery/pm/defconfig
+++ b/nuttx/configs/stm32f4discovery/pm/defconfig
@@ -386,7 +386,7 @@ CONFIG_PM_BUTTON_ACTIVITY=10
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/posix_spawn/defconfig b/nuttx/configs/stm32f4discovery/posix_spawn/defconfig
index 7af10213a..615f6383d 100644
--- a/nuttx/configs/stm32f4discovery/posix_spawn/defconfig
+++ b/nuttx/configs/stm32f4discovery/posix_spawn/defconfig
@@ -375,7 +375,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/usbnsh/defconfig b/nuttx/configs/stm32f4discovery/usbnsh/defconfig
index 485093022..ccde00292 100644
--- a/nuttx/configs/stm32f4discovery/usbnsh/defconfig
+++ b/nuttx/configs/stm32f4discovery/usbnsh/defconfig
@@ -384,7 +384,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/stm32f4discovery/winbuild/defconfig b/nuttx/configs/stm32f4discovery/winbuild/defconfig
index 8cd376545..9f3b1067f 100644
--- a/nuttx/configs/stm32f4discovery/winbuild/defconfig
+++ b/nuttx/configs/stm32f4discovery/winbuild/defconfig
@@ -248,7 +248,7 @@ CONFIG_ARCH_HAVE_IRQBUTTONS=y
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32ldiscovery/nsh/defconfig b/nuttx/configs/stm32ldiscovery/nsh/defconfig
index 4f9d0ccb5..8723a5c95 100644
--- a/nuttx/configs/stm32ldiscovery/nsh/defconfig
+++ b/nuttx/configs/stm32ldiscovery/nsh/defconfig
@@ -308,7 +308,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/stm32vldiscovery/nsh/defconfig b/nuttx/configs/stm32vldiscovery/nsh/defconfig
index ff3e08395..31d534cef 100644
--- a/nuttx/configs/stm32vldiscovery/nsh/defconfig
+++ b/nuttx/configs/stm32vldiscovery/nsh/defconfig
@@ -232,7 +232,7 @@ CONFIG_NSH_DISABLEBG=y
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/sure-pic32mx/nsh/defconfig b/nuttx/configs/sure-pic32mx/nsh/defconfig
index ad808878e..8f6c7dcbc 100644
--- a/nuttx/configs/sure-pic32mx/nsh/defconfig
+++ b/nuttx/configs/sure-pic32mx/nsh/defconfig
@@ -296,7 +296,7 @@ CONFIG_ARCH_DBDP11215=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/sure-pic32mx/usbnsh/defconfig b/nuttx/configs/sure-pic32mx/usbnsh/defconfig
index 00a11f83f..3c04eb51f 100644
--- a/nuttx/configs/sure-pic32mx/usbnsh/defconfig
+++ b/nuttx/configs/sure-pic32mx/usbnsh/defconfig
@@ -297,7 +297,7 @@ CONFIG_ARCH_DBDP11215=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/teensy/hello/defconfig b/nuttx/configs/teensy/hello/defconfig
index ebab93ef4..582891e0e 100644
--- a/nuttx/configs/teensy/hello/defconfig
+++ b/nuttx/configs/teensy/hello/defconfig
@@ -166,7 +166,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/teensy/nsh/defconfig b/nuttx/configs/teensy/nsh/defconfig
index 320d8d6e6..432eec438 100644
--- a/nuttx/configs/teensy/nsh/defconfig
+++ b/nuttx/configs/teensy/nsh/defconfig
@@ -167,7 +167,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/teensy/usbmsc/defconfig b/nuttx/configs/teensy/usbmsc/defconfig
index eff8ed290..c6464649a 100644
--- a/nuttx/configs/teensy/usbmsc/defconfig
+++ b/nuttx/configs/teensy/usbmsc/defconfig
@@ -165,7 +165,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/tm4c123g-launchpad/nsh/defconfig b/nuttx/configs/tm4c123g-launchpad/nsh/defconfig
index 2cac6e0ef..4e716c034 100644
--- a/nuttx/configs/tm4c123g-launchpad/nsh/defconfig
+++ b/nuttx/configs/tm4c123g-launchpad/nsh/defconfig
@@ -236,7 +236,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/twr-k60n512/nsh/defconfig b/nuttx/configs/twr-k60n512/nsh/defconfig
index c90cebadc..19bbb41b0 100644
--- a/nuttx/configs/twr-k60n512/nsh/defconfig
+++ b/nuttx/configs/twr-k60n512/nsh/defconfig
@@ -228,7 +228,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/ubw32/nsh/defconfig b/nuttx/configs/ubw32/nsh/defconfig
index 208ea8587..ec1033bf0 100644
--- a/nuttx/configs/ubw32/nsh/defconfig
+++ b/nuttx/configs/ubw32/nsh/defconfig
@@ -322,7 +322,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/us7032evb1/nsh/defconfig b/nuttx/configs/us7032evb1/nsh/defconfig
index da3c982ff..e442982ce 100644
--- a/nuttx/configs/us7032evb1/nsh/defconfig
+++ b/nuttx/configs/us7032evb1/nsh/defconfig
@@ -160,7 +160,7 @@ CONFIG_NSH_MMCSDMINOR=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/us7032evb1/ostest/defconfig b/nuttx/configs/us7032evb1/ostest/defconfig
index 3f5fb608f..434de2836 100644
--- a/nuttx/configs/us7032evb1/ostest/defconfig
+++ b/nuttx/configs/us7032evb1/ostest/defconfig
@@ -159,7 +159,7 @@ CONFIG_ARCH_BUTTONS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/viewtool-stm32f107/highpri/defconfig b/nuttx/configs/viewtool-stm32f107/highpri/defconfig
index 2c170a650..5d087dc7e 100644
--- a/nuttx/configs/viewtool-stm32f107/highpri/defconfig
+++ b/nuttx/configs/viewtool-stm32f107/highpri/defconfig
@@ -358,7 +358,7 @@ CONFIG_VIEWTOOL_TIM6_PERIOD=36000
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/viewtool-stm32f107/netnsh/defconfig b/nuttx/configs/viewtool-stm32f107/netnsh/defconfig
index d3ccd5e6a..1df27b091 100644
--- a/nuttx/configs/viewtool-stm32f107/netnsh/defconfig
+++ b/nuttx/configs/viewtool-stm32f107/netnsh/defconfig
@@ -429,7 +429,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/viewtool-stm32f107/nsh/defconfig b/nuttx/configs/viewtool-stm32f107/nsh/defconfig
index 2113c4241..ccd20ec0d 100644
--- a/nuttx/configs/viewtool-stm32f107/nsh/defconfig
+++ b/nuttx/configs/viewtool-stm32f107/nsh/defconfig
@@ -406,7 +406,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/vsn/nsh/defconfig b/nuttx/configs/vsn/nsh/defconfig
index 79deec5c5..b77a58a5c 100644
--- a/nuttx/configs/vsn/nsh/defconfig
+++ b/nuttx/configs/vsn/nsh/defconfig
@@ -387,7 +387,7 @@ CONFIG_NSH_MMCSDSLOTNO=0
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_CPULOAD is not set
diff --git a/nuttx/configs/xtrs/nsh/defconfig b/nuttx/configs/xtrs/nsh/defconfig
index 262797c68..07ea7f2b9 100644
--- a/nuttx/configs/xtrs/nsh/defconfig
+++ b/nuttx/configs/xtrs/nsh/defconfig
@@ -120,7 +120,7 @@ CONFIG_NSH_MMCSDMINOR=0
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/xtrs/ostest/defconfig b/nuttx/configs/xtrs/ostest/defconfig
index c28097a34..8367db6b9 100644
--- a/nuttx/configs/xtrs/ostest/defconfig
+++ b/nuttx/configs/xtrs/ostest/defconfig
@@ -119,7 +119,7 @@ CONFIG_ARCH_BOARD="xtrs"
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/xtrs/pashello/defconfig b/nuttx/configs/xtrs/pashello/defconfig
index 88445242c..b62be778e 100644
--- a/nuttx/configs/xtrs/pashello/defconfig
+++ b/nuttx/configs/xtrs/pashello/defconfig
@@ -120,7 +120,7 @@ CONFIG_ARCH_BOARD="xtrs"
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/z16f2800100zcog/nsh/defconfig b/nuttx/configs/z16f2800100zcog/nsh/defconfig
index 9127639fd..42b49768f 100644
--- a/nuttx/configs/z16f2800100zcog/nsh/defconfig
+++ b/nuttx/configs/z16f2800100zcog/nsh/defconfig
@@ -192,7 +192,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/z16f2800100zcog/ostest/defconfig b/nuttx/configs/z16f2800100zcog/ostest/defconfig
index e13799c3c..64a3aab4a 100644
--- a/nuttx/configs/z16f2800100zcog/ostest/defconfig
+++ b/nuttx/configs/z16f2800100zcog/ostest/defconfig
@@ -167,7 +167,7 @@ CONFIG_ARCH_LEDS=y
 # RTOS Features
 #
 # CONFIG_BOARD_INITIALIZE is not set
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
diff --git a/nuttx/configs/z16f2800100zcog/pashello/defconfig b/nuttx/configs/z16f2800100zcog/pashello/defconfig
index eac9d5203..e4205c8af 100644
--- a/nuttx/configs/z16f2800100zcog/pashello/defconfig
+++ b/nuttx/configs/z16f2800100zcog/pashello/defconfig
@@ -143,7 +143,7 @@ CONFIG_ARCH_LEDS=y
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=200
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/z80sim/nsh/defconfig b/nuttx/configs/z80sim/nsh/defconfig
index f576bb755..404c55552 100644
--- a/nuttx/configs/z80sim/nsh/defconfig
+++ b/nuttx/configs/z80sim/nsh/defconfig
@@ -120,7 +120,7 @@ CONFIG_NSH_MMCSDMINOR=0
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/z80sim/ostest/defconfig b/nuttx/configs/z80sim/ostest/defconfig
index e8a005a39..58e8a0752 100644
--- a/nuttx/configs/z80sim/ostest/defconfig
+++ b/nuttx/configs/z80sim/ostest/defconfig
@@ -119,7 +119,7 @@ CONFIG_ARCH_BOARD="z80sim"
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/z80sim/pashello/defconfig b/nuttx/configs/z80sim/pashello/defconfig
index 7f5ca7d20..10300460a 100644
--- a/nuttx/configs/z80sim/pashello/defconfig
+++ b/nuttx/configs/z80sim/pashello/defconfig
@@ -119,7 +119,7 @@ CONFIG_ARCH_BOARD="z80sim"
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/z8encore000zco/ostest/defconfig b/nuttx/configs/z8encore000zco/ostest/defconfig
index ea4a3974c..29b9ec6ba 100644
--- a/nuttx/configs/z8encore000zco/ostest/defconfig
+++ b/nuttx/configs/z8encore000zco/ostest/defconfig
@@ -135,7 +135,7 @@ CONFIG_ARCH_HAVE_LEDS=y
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/z8f64200100kit/ostest/defconfig b/nuttx/configs/z8f64200100kit/ostest/defconfig
index 6947517b8..3d1df0157 100644
--- a/nuttx/configs/z8f64200100kit/ostest/defconfig
+++ b/nuttx/configs/z8f64200100kit/ostest/defconfig
@@ -135,7 +135,7 @@ CONFIG_ARCH_HAVE_LEDS=y
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/zkit-arm-1769/hello/defconfig b/nuttx/configs/zkit-arm-1769/hello/defconfig
index 3257f4175..0f6b5b9a3 100644
--- a/nuttx/configs/zkit-arm-1769/hello/defconfig
+++ b/nuttx/configs/zkit-arm-1769/hello/defconfig
@@ -282,7 +282,7 @@ CONFIG_DISABLE_MQUEUE=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/zkit-arm-1769/nsh/defconfig b/nuttx/configs/zkit-arm-1769/nsh/defconfig
index b1bb94171..f358a10b8 100644
--- a/nuttx/configs/zkit-arm-1769/nsh/defconfig
+++ b/nuttx/configs/zkit-arm-1769/nsh/defconfig
@@ -285,7 +285,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/zkit-arm-1769/nxhello/defconfig b/nuttx/configs/zkit-arm-1769/nxhello/defconfig
index 1efc2d799..a7ca866ef 100644
--- a/nuttx/configs/zkit-arm-1769/nxhello/defconfig
+++ b/nuttx/configs/zkit-arm-1769/nxhello/defconfig
@@ -285,7 +285,7 @@ CONFIG_DISABLE_OS_API=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/zkit-arm-1769/thttpd/defconfig b/nuttx/configs/zkit-arm-1769/thttpd/defconfig
index 40370dba7..b46b1665a 100644
--- a/nuttx/configs/zkit-arm-1769/thttpd/defconfig
+++ b/nuttx/configs/zkit-arm-1769/thttpd/defconfig
@@ -282,7 +282,7 @@ CONFIG_DISABLE_MQUEUE=y
 #
 # Clocks and Timers
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 # CONFIG_SYSTEM_TIME64 is not set
 # CONFIG_CLOCK_MONOTONIC is not set
 # CONFIG_JULIAN_TIME is not set
diff --git a/nuttx/configs/zp214xpa/nsh/defconfig b/nuttx/configs/zp214xpa/nsh/defconfig
index 781272280..36e9e65d3 100644
--- a/nuttx/configs/zp214xpa/nsh/defconfig
+++ b/nuttx/configs/zp214xpa/nsh/defconfig
@@ -166,7 +166,7 @@ CONFIG_NSH_MMCSDMINOR=0
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/configs/zp214xpa/nxlines/defconfig b/nuttx/configs/zp214xpa/nxlines/defconfig
index 5bbe4ae83..4b80da4f7 100644
--- a/nuttx/configs/zp214xpa/nxlines/defconfig
+++ b/nuttx/configs/zp214xpa/nxlines/defconfig
@@ -165,7 +165,7 @@ CONFIG_ARCH_BOARD="zp214xpa"
 #
 # RTOS Features
 #
-CONFIG_MSEC_PER_TICK=10
+CONFIG_USEC_PER_TICK=10000
 CONFIG_RR_INTERVAL=0
 # CONFIG_SCHED_INSTRUMENTATION is not set
 CONFIG_TASK_NAME_SIZE=0
diff --git a/nuttx/include/limits.h b/nuttx/include/limits.h
index 4d959d153..781901999 100644
--- a/nuttx/include/limits.h
+++ b/nuttx/include/limits.h
@@ -1,7 +1,7 @@
 /********************************************************************************
  * include/limits.h
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -149,18 +149,19 @@
  *
  * _POSIX_TIMER_MAX is the per-process number of timers.
  *
- * _POSIX_CLOCKRES_MIN is the resolution of the CLOCK_REALTIME clock in nanoseconds.
- * CLOCK_REALTIME is controlled by the NuttX system time.  The default value is the
- * system timer which has a resolution of 10 milliseconds.  This default setting can
- * be overridden by defining the clock interval in milliseconds as CONFIG_MSEC_PER_TICK
- * in the board configuration file.
+ * _POSIX_CLOCKRES_MIN is the resolution of the CLOCK_REALTIME clock in
+ *    nanoseconds.  CLOCK_REALTIME is controlled by the NuttX system time.
+ *    The default value is the system timer which has a resolution of 1000
+ *    microseconds.  This default setting can be overridden by defining the
+ *    clock interval in microseconds as CONFIG_USEC_PER_TICK in the NuttX
+ *    configuration file.
  */
 
 #define _POSIX_DELAYTIMER_MAX 32
 #define _POSIX_TIMER_MAX      32
 
-#ifdef CONFIG_MSEC_PER_TICK
-# define _POSIX_CLOCKRES_MIN  ((CONFIG_MSEC_PER_TICK)*1000000)
+#ifdef CONFIG_USEC_PER_TICK
+# define _POSIX_CLOCKRES_MIN  ((CONFIG_USEC_PER_TICK)*1000)
 #else
 # define _POSIX_CLOCKRES_MIN  (10*1000000)
 #endif
diff --git a/nuttx/include/nuttx/clock.h b/nuttx/include/nuttx/clock.h
index 210310603..509d624d2 100644
--- a/nuttx/include/nuttx/clock.h
+++ b/nuttx/include/nuttx/clock.h
@@ -93,8 +93,8 @@
  * of milliseconds between calls from the processor-specific logic to
  * sched_process_timer().  The default value of MSEC_PER_TICK is 10
  * milliseconds (100KHz).  However, this default setting can be overridden
- * by defining the interval in milliseconds as CONFIG_MSEC_PER_TICK in the
- * board configuration file.
+ * by defining the interval in microseconds as CONFIG_USEC_PER_TICK in the
+ * NuttX configuration file.
  *
  * The following calculations are only accurate when (1) there is no
  * truncation involved and (2) the underlying system timer is an even
@@ -102,29 +102,44 @@
  * to redefine all of the following.
  */
 
-#ifdef CONFIG_MSEC_PER_TICK
-# define MSEC_PER_TICK        (CONFIG_MSEC_PER_TICK)
+#ifdef CONFIG_USEC_PER_TICK
+# define USEC_PER_TICK        (CONFIG_USEC_PER_TICK)
 #else
-# define MSEC_PER_TICK        (10)
+# define USEC_PER_TICK        (10000)
 #endif
 
-#define TICK_PER_DSEC         (MSEC_PER_DSEC / MSEC_PER_TICK)            /* Truncates! */
-#define TICK_PER_SEC          (MSEC_PER_SEC / MSEC_PER_TICK)             /* Truncates! */
-#define NSEC_PER_TICK         (MSEC_PER_TICK * NSEC_PER_MSEC)            /* Exact */
-#define USEC_PER_TICK         (MSEC_PER_TICK * USEC_PER_MSEC)            /* Exact */
+/* MSEC_PER_TICK can be very inaccurate if CONFIG_USEC_PER_TICK is not an
+ * even multiple of milliseconds.  Calculations using USEC_PER_TICK are
+ * preferred for that reason (at the risk of overflow)
+ */
+
+#define TICK_PER_DSEC         (USEC_PER_DSEC / USEC_PER_TICK)            /* Truncates! */
+#define TICK_PER_SEC          (USEC_PER_SEC / USEC_PER_TICK)             /* Truncates! */
+#define MSEC_PER_TICK         (USEC_PER_MSEC / USEC_PER_TICK)            /* Truncates! */
+#define NSEC_PER_TICK         (USEC_PER_TICK * NSEC_PER_USEC)            /* Exact */
 
 #define NSEC2TICK(nsec)       (((nsec)+(NSEC_PER_TICK/2))/NSEC_PER_TICK) /* Rounds */
 #define USEC2TICK(usec)       (((usec)+(USEC_PER_TICK/2))/USEC_PER_TICK) /* Rounds */
-#define MSEC2TICK(msec)       (((msec)+(MSEC_PER_TICK/2))/MSEC_PER_TICK) /* Rounds */
-#define DSEC2TICK(dsec)       MSEC2TICK((dsec)*MSEC_PER_DSEC)
+#define DSEC2TICK(dsec)       MSEC2TICK((dsec)*MSEC_PER_DSEC)            /* Exact */
 #define SEC2TICK(sec)         MSEC2TICK((sec)*MSEC_PER_SEC)              /* Exact */
 
+#if (MSEC_PER_TICK * USEC_PER_MSEC) == USEC_PER_TICK
+#  define MSEC2TICK(msec)     (((msec)+(MSEC_PER_TICK/2))/MSEC_PER_TICK) /* Rounds */
+#else
+#  define MSEC2TICK(msec)     USEC2TICK(msec * 1000)                     /* Rounds */
+#endif
+
 #define TICK2NSEC(tick)       ((tick)*NSEC_PER_TICK)                     /* Exact */
 #define TICK2USEC(tick)       ((tick)*USEC_PER_TICK)                     /* Exact */
-#define TICK2MSEC(tick)       ((tick)*MSEC_PER_TICK)                     /* Exact */
 #define TICK2DSEC(tick)       (((tick)+(TICK_PER_DSEC/2))/TICK_PER_DSEC) /* Rounds */
 #define TICK2SEC(tick)        (((tick)+(TICK_PER_SEC/2))/TICK_PER_SEC)   /* Rounds */
 
+#if (MSEC_PER_TICK * USEC_PER_MSEC) == USEC_PER_TICK
+#define TICK2USEC(tick)       ((tick)*MSEC_PER_TICK)                     /* Exact */
+#else
+#  define TICK2MSEC(tick)     (((tick)*USEC_PER_TICK)/USEC_PER_MSEC)     /* Rounds */
+#endif
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/
diff --git a/nuttx/include/time.h b/nuttx/include/time.h
index 414e19995..b0e6a0c25 100644
--- a/nuttx/include/time.h
+++ b/nuttx/include/time.h
@@ -55,13 +55,13 @@
  * replaced with CLOCKS_PER_SEC.  Both are defined here.
  *
  * The default value is 100Hz, but this default setting can be overridden by
- * defining the clock interval in milliseconds as CONFIG_MSEC_PER_TICK in the
+ * defining the clock interval in microseconds as CONFIG_USEC_PER_TICK in the
  * board configuration file.
  */
 
-#ifdef CONFIG_MSEC_PER_TICK
-# define CLK_TCK           (1000/CONFIG_MSEC_PER_TICK)
-# define CLOCKS_PER_SEC    (1000/CONFIG_MSEC_PER_TICK)
+#ifdef CONFIG_USEC_PER_TICK
+# define CLK_TCK           (1000000/CONFIG_USEC_PER_TICK)
+# define CLOCKS_PER_SEC    (1000000/CONFIG_USEC_PER_TICK)
 #else
 # define CLK_TCK           (100)
 # define CLOCKS_PER_SEC    (100)
diff --git a/nuttx/sched/Kconfig b/nuttx/sched/Kconfig
index 07d1194da..54cb698d7 100644
--- a/nuttx/sched/Kconfig
+++ b/nuttx/sched/Kconfig
@@ -65,21 +65,33 @@ config SCHED_TICKLESS
 		additional plaform specific interfaces that must be provided as
 		defined include/nuttx/arch.h
 
-config MSEC_PER_TICK
+config USEC_PER_TICK
 	int "Milliseconds per system timer tick"
-	default 10 if !SCHED_TICKLESS
-	default 1 if SCHED_TICKLESS
+	default 10000 if !SCHED_TICKLESS
+	default 100 if SCHED_TICKLESS
 	---help---
-		The default system timer is 100Hz or MSEC_PER_TICK=10.  This setting
-		may be defined to inform NuttX that the processor hardware is providing
-		system timer interrupts at some interrupt interval other than 10 msec.
+		In the "normal" configuration where system time is provided by a
+		periodic timer interrupt, the default system timer is expected to
+		run at 100Hz or USEC_PER_TICK=10000.  This setting must be defined
+		to inform of NuttX the interval that the the processor hardware is
+		providing system timer interrupts to the OS.
 
 		If SCHED_TICKLESS is selected, then there are no system timer
-		interrupts.  In this case, MSEC_PER_TICK does not control any timer
+		interrupts.  In this case, USEC_PER_TICK does not control any timer
 		rates.  Rather, it only determines the resolution of time reported
 		by clock_systimer() and the resolution of times that can be set for
-		certain delays including watchdog timers and delayed work.  In these
-		cases it is better to have the MSEC_PER_TICK as low as possible.
+		certain delays including watchdog timers and delayed work.  In this
+		case there is a tradeoff:  It is better to have the USEC_PER_TICK as
+		low as possible for higher timing resolution.  However, the the time
+		is currently held in 'unsigned int' on some systems, this may be
+		16-bits but on most contemporary systems it will be 32-bits.  In
+		either case, smaller values of USEC_PER_TICK will reduce the range
+		of values that delays that can be represented.  So the tradeoff is
+		between range and resolution (you could also modify the code to use
+		a 64-bit value if you really want both).
+
+		The default, 100 microseconds, will provide for a range of delays
+		up to 120 hours.
 
 if !SCHED_TICKLESS
 
@@ -101,7 +113,7 @@ config SYSTEM_TIME64
 	default n
 	---help---
 		The system timer is incremented at the rate determined by
-		MSEC_PER_TICK, typically at 100Hz. The count at any given time is
+		USEC_PER_TICK, typically at 100Hz. The count at any given time is
 		then the "uptime" in units of system timer ticks.  By default, the
 		system time is 32-bits wide.  Those defaults provide a range of about
 		13.6 years which is probably a sufficient range for "uptime".
-- 
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