原创 STM32使用FSMC控制sram例程

一、基本概念

1.与非总线复用的16位SRAM接口
FSMC配置
SRAM存储器和NOR闪存存储器共用相同的FSMC存储块，所用的协议依不同的存储器类型而有所不同。
控制SRAM存储器，FSMC应该具有下述功能：
●
使用或禁止地址/数据总线的复用功能。
●
选择所用的存储器类型：NOR闪存、SRAM或PSRAM。
●
定义外部存储器的数据总线宽度：8或16位。
●
使用或关闭扩展模式：扩展模式用于访问那些具有不同读写操作时序的存储器。
正如配置NOR闪存存储器一样，用户必须按照SRAM存储器的数据手册给出的时序数据，计算和设置下列参数：
●
ADDSET：地址建立时间
●
ADDHOLD：地址保持时间
●
DATAST：数据建立时间

二、例程

1. FSMC_SRAM.C

/******************** (C) COPYRIGHT 2008 STMicroelectronics ********************
* File Name : fsmc_sram.c
* Author : MCD Application Team
* Version : V2.0.1
* Date : 06/13/2008
* Description : This file provides a set of functions needed to drive the
* IS61WV51216BLL SRAM memory mounted on STM3210E-EVAL board.
********************************************************************************
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "fsmc_sram.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define Bank1_SRAM3_ADDR ((u32)0x68000000)

#define SRAM_WRITE(Address, Data) (*(vu16 *)(Address) = (Data))

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/*******************************************************************************
* Function Name : FSMC_SRAM_Init
* Description : Configures the FSMC and GPIOs to interface with the SRAM memory.
* This function must be called before any write/read operation
* on the SRAM.
* Input : None
* Output : None
* Return : None
*******************************************************************************/
void FSMC_SRAM_Init(void)
{
FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure;
FSMC_NORSRAMTimingInitTypeDef p;
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOG | RCC_APB2Periph_GPIOE |
RCC_APB2Periph_GPIOF, ENABLE);

/*-- GPIO Configuration ------------------------------------------------------*/
/* SRAM Data lines configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_8 | GPIO_Pin_9 |
GPIO_Pin_10 | GPIO_Pin_14 | GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 |
GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 |
GPIO_Pin_15;
GPIO_Init(GPIOE, &GPIO_InitStructure);

/* SRAM Address lines configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 |
GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_12 | GPIO_Pin_13 |
GPIO_Pin_14 | GPIO_Pin_15;
GPIO_Init(GPIOF, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 |
GPIO_Pin_4 | GPIO_Pin_5;
GPIO_Init(GPIOG, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13;
GPIO_Init(GPIOD, &GPIO_InitStructure);

/* NOE and NWE configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 |GPIO_Pin_5;
GPIO_Init(GPIOD, &GPIO_InitStructure);

/* NE3 configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_Init(GPIOG, &GPIO_InitStructure);

/* NBL0, NBL1 configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
GPIO_Init(GPIOE, &GPIO_InitStructure);

/*-- FSMC Configuration ------------------------------------------------------*/
p.FSMC_AddressSetupTime = 0;
p.FSMC_AddressHoldTime = 0;
p.FSMC_DataSetupTime = 2;
p.FSMC_BusTurnAroundDuration = 0;
p.FSMC_CLKDivision = 0;
p.FSMC_DataLatency = 0;
p.FSMC_AccessMode = FSMC_AccessMode_A;

FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM3;
FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_SRAM;
FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_AsyncWait = FSMC_AsyncWait_Disable;
FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p;
FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p;

FSMC_NORSRAMInit(&FSMC_NORSRAMInitStructure);

/* Enable FSMC Bank1_SRAM Bank */
FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM3, ENABLE);
}

/*******************************************************************************
* Function Name : FSMC_SRAM_WriteBuffer
* Description : Writes a Half-word buffer to the FSMC SRAM memory.
* Input : - pBuffer : pointer to buffer.
* - WriteAddr : SRAM memory internal address from which the data
* will be written.
* - NumHalfwordToWrite : number of half-words to write.
*
* Output : None
* Return : None
*******************************************************************************/
void FSMC_SRAM_WriteBuffer(u16* pBuffer, u32 WriteAddr, u32 NumHalfwordToWrite)
{
for(; NumHalfwordToWrite != 0; NumHalfwordToWrite--) /* while there is data to write */
{
/* Transfer data to the memory */
*(u16 *) (Bank1_SRAM3_ADDR + WriteAddr) = *pBuffer++;

/* Increment the address*/
WriteAddr += 2;
}
}