diff options
Diffstat (limited to 'nuttx/include')
| -rw-r--r-- | nuttx/include/limits.h | 17 | ||||
| -rw-r--r-- | nuttx/include/nuttx/clock.h | 39 | ||||
| -rw-r--r-- | nuttx/include/time.h | 8 |
3 files changed, 40 insertions, 24 deletions
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) |