/************************************************************************************
* arch/arm/src/lpc17xx/lpc17_emacram.h
*
* Copyright (C) 2010 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
#ifndef __ARCH_ARM_SRC_LPC17XX_LPC17_EMACRAM_H
#define __ARCH_ARM_SRC_LPC17XX_LPC17_EMACRAM_H
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include "chip.h"
#include "chip/lpc17_memorymap.h"
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Default, no-EMAC Case ************************************************************/
/* Assume that all of AHB SRAM will be available for heap. If this is not true, then
* LPC17_BANK0_HEAPSIZE will be undefined and redefined below.
*/
#undef LPC17_BANK0_HEAPBASE
#undef LPC17_BANK0_HEAPSIZE
#ifdef LPC17_HAVE_BANK0
# define LPC17_BANK0_HEAPBASE LPC17_SRAM_BANK0
# define LPC17_BANK0_HEAPSIZE LPC17_BANK0_SIZE
#endif
/* Is networking enabled? Is the LPC17xx Ethernet device enabled? Does this chip have
* and Ethernet controlloer? Yes... then we will replace the above default definitions.
*/
#if defined(CONFIG_NET) && defined(CONFIG_LPC17_ETHERNET) && LPC17_NETHCONTROLLERS > 0
/* EMAC RAM Configuration ***********************************************************/
/* Is AHB SRAM available? */
#ifndef LPC17_HAVE_BANK0
# error "AHB SRAM Bank0 is not available for EMAC RAM"
#endif
/* Number of Tx descriptors */
#ifndef CONFIG_NET_NTXDESC
# define CONFIG_NET_NTXDESC 18
#endif
/* Number of Rx descriptors */
#ifndef CONFIG_NET_NRXDESC
# define CONFIG_NET_NRXDESC 18
#endif
/* Size of the region at the beginning of AHB SRAM 0 set set aside for the EMAC.
* This size must fit within AHB SRAM Bank 0 and also be a multiple of 32-bit
* words.
*/
#ifndef CONFIG_NET_EMACRAM_SIZE
# define CONFIG_NET_EMACRAM_SIZE LPC17_BANK0_SIZE
#endif
#if CONFIG_NET_EMACRAM_SIZE > LPC17_BANK0_SIZE
# error "EMAC RAM size cannot exceed the size of AHB SRAM Bank 0"
#endif
#if (CONFIG_NET_EMACRAM_SIZE & 3) != 0
# error "EMAC RAM size must be in multiples of 32-bit words"
#endif
/* Determine is there is any meaningful space left at the end of AHB Bank 0 that
* could be added to the heap.
*/
#undef LPC17_BANK0_HEAPBASE
#undef LPC17_BANK0_HEAPSIZE
#if CONFIG_NET_EMACRAM_SIZE < (LPC17_BANK0_SIZE-128)
# define LPC17_BANK0_HEAPBASE (LPC17_SRAM_BANK0 + CONFIG_NET_EMACRAM_SIZE)
# define LPC17_BANK0_HEAPSIZE (LPC17_BANK0_SIZE - CONFIG_NET_EMACRAM_SIZE)
#endif
/* Memory at the beginning of AHB SRAM, Bank 0 is set aside for EMAC Tx and Rx
* descriptors. The position is not controllable, only the size of the region
* is controllable.
*/
#define LPC17_EMACRAM_BASE LPC17_SRAM_BANK0
#define LPC17_EMACRAM_SIZE CONFIG_NET_EMACRAM_SIZE
/* Descriptor Memory Layout *********************************************************/
/* EMAC DMA RAM and descriptor definitions. The configured number of descriptors
* will determine the organization and the size of the descriptor and status tables.
* There is a complex interaction between the maximum packet size (CONFIG_NET_BUFSIZE)
* and the number of Rx and Tx descriptors that can be suppored (CONFIG_NET_NRXDESC
* and CONFIG_NET_NTXDESC): Small buffers -> more packets. This is something that
* needs to be tuned for you system.
*
* For a 16Kb SRAM region, here is the relationship:
*
* 16384 <= ntx * (pktsize + 8 + 4) + nrx * (pktsize + 8 + 8)
*
* If ntx == nrx and pktsize == 424, then you could have
* ntx = nrx = 18.
*
* An example with all of the details:
*
* NTXDESC=18 NRXDESC=18 CONFIG_NET_EMACRAM_SIZE=16Kb CONFIG_NET_BUFSIZE=420:
* LPC17_TXDESCTAB_SIZE = 18*8 = 144
* LPC17_TXSTATTAB_SIZE = 18*4 = 72
* LPC17_TXTAB_SIZE = 216
*
* LPC17_RXDESCTAB_SIZE = 16*8 = 144
* LPC17_RXSTATTAB_SIZE = 16*8 = 144
* LPC17_TXTAB_SIZE = 288
*
* LPC17_DESCTAB_SIZE = 504
* LPC17_DESC_BASE = LPC17_SRAM_BANK0 + 0x00004000 - 504
* = LPC17_SRAM_BANK0 + 0x00003e08
* LPC17_TXDESC_BASE = LPC17_SRAM_BANK0 + 0x00003e08
* LPC17_TXSTAT_BASE = LPC17_SRAM_BANK0 + 0x00003e98
* LPC17_RXDESC_BASE = LPC17_SRAM_BANK0 + 0x00003ee0
* LPC17_RXSTAT_BASE = LPC17_SRAM_BANK0 + 0x00003f70
*
* LPC17_PKTMEM_BASE = LPC17_SRAM_BANK0
* LPC17_PKTMEM_SIZE = 0x00004000-504 = 0x00003e40
* LPC17_PKTMEM_END = LPC17_SRAM_BANK0 + 0x00003e08
* LPC17_MAXPACKET_SIZE = ((420 + 3 + 2) & ~3) = 424
* LPC17_NTXPKTS = 18
* LPC17_NRXPKTS = 18
* LPC17_TXBUFFER_SIZE = 18 * 424 = 0x00001dd0
* LPC17_RXBUFFER_SIZE = 18 * 424 = 0x00001dd0
* LPC17_BUFFER_SIZE = 0x00003ba0
* LPC17_BUFFER_BASE = LPC17_SRAM_BANK0
* LPC17_TXBUFFER_BASE = LPC17_SRAM_BANK0
* LPC17_RXBUFFER_BASE = LPC17_SRAM_BANK0 + 0x00001dd0
* LPC17_BUFFER_END = LPC17_SRAM_BANK0 + 0x00003ba0
*
* Then the check LPC17_BUFFER_END < LPC17_PKTMEM_END passes. The amount of
* unused memory is small: 0x00003e08-0x00003ba0 or about 616 bytes -- not
* enough for two more packets.
*
* [It is also possible, with some effort, to reclaim any unused
* SRAM for the use in the heap. But that has not yet been pursued.]
*/
#define LPC17_TXDESCTAB_SIZE (CONFIG_NET_NTXDESC*LPC17_TXDESC_SIZE)
#define LPC17_TXSTATTAB_SIZE (CONFIG_NET_NTXDESC*LPC17_TXSTAT_SIZE)
#define LPC17_TXTAB_SIZE (LPC17_TXDESCTAB_SIZE+LPC17_TXSTATTAB_SIZE)
#define LPC17_RXDESCTAB_SIZE (CONFIG_NET_NRXDESC*LPC17_RXDESC_SIZE)
#define LPC17_RXSTATTAB_SIZE (CONFIG_NET_NRXDESC*LPC17_RXSTAT_SIZE)
#define LPC17_RXTAB_SIZE (LPC17_RXDESCTAB_SIZE+LPC17_RXSTATTAB_SIZE)
#define LPC17_DESCTAB_SIZE (LPC17_TXTAB_SIZE+LPC17_RXTAB_SIZE)
/* Descriptor table memory organization. Descriptor tables are packed at
* the end of AHB SRAM, Bank 0. The beginning of bank 0 is reserved for
* packet memory.
*/
#define LPC17_DESC_BASE (LPC17_EMACRAM_BASE+LPC17_EMACRAM_SIZE-LPC17_DESCTAB_SIZE)
#define LPC17_TXDESC_BASE LPC17_DESC_BASE
#define LPC17_TXSTAT_BASE (LPC17_TXDESC_BASE+LPC17_TXDESCTAB_SIZE)
#define LPC17_RXDESC_BASE (LPC17_TXSTAT_BASE+LPC17_TXSTATTAB_SIZE)
#define LPC17_RXSTAT_BASE (LPC17_RXDESC_BASE + LPC17_RXDESCTAB_SIZE)
/* Now carve up the beginning of SRAM for packet memory. The size of a
* packet buffer is related to the size of the MTU. We'll round sizes up
* to multiples of 256 bytes.
*/
#define LPC17_PKTMEM_BASE LPC17_EMACRAM_BASE
#define LPC17_PKTMEM_SIZE (LPC17_EMACRAM_SIZE-LPC17_DESCTAB_SIZE)
#define LPC17_PKTMEM_END (LPC17_EMACRAM_BASE+LPC17_PKTMEM_SIZE)
#define LPC17_MAXPACKET_SIZE ((CONFIG_NET_BUFSIZE + CONFIG_NET_GUARDSIZE + 3) & ~3)
#define LPC17_NTXPKTS CONFIG_NET_NTXDESC
#define LPC17_NRXPKTS CONFIG_NET_NRXDESC
#define LPC17_TXBUFFER_SIZE (LPC17_NTXPKTS * LPC17_MAXPACKET_SIZE)
#define LPC17_RXBUFFER_SIZE (LPC17_NRXPKTS * LPC17_MAXPACKET_SIZE)
#define LPC17_BUFFER_SIZE (LPC17_TXBUFFER_SIZE + LPC17_RXBUFFER_SIZE)
#define LPC17_BUFFER_BASE LPC17_PKTMEM_BASE
#define LPC17_TXBUFFER_BASE LPC17_BUFFER_BASE
#define LPC17_RXBUFFER_BASE (LPC17_TXBUFFER_BASE + LPC17_TXBUFFER_SIZE)
#define LPC17_BUFFER_END (LPC17_BUFFER_BASE + LPC17_BUFFER_SIZE)
#if LPC17_BUFFER_END > LPC17_PKTMEM_END
# error "Packet memory overlaps descriptor tables"
#endif
/************************************************************************************
* Public Types
************************************************************************************/
/************************************************************************************
* Public Data
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
#endif /* CONFIG_NET && CONFIG_LPC17_ETHERNET && LPC17_NETHCONTROLLERS > 0*/
#endif /* __ARCH_ARM_SRC_LPC17XX_LPC17_EMACRAM_H */
