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;
? }??
}
/*******************************************************************************
* Function Name? : FSMC_SRAM_ReadBuffer
* Description??? : Reads a block of data from the FSMC SRAM memory.
* Input????????? : - pBuffer : pointer to the buffer that receives the data read
*??????????????????? from the SRAM memory.
*????????????????? - ReadAddr : SRAM memory internal address to read from.
*????????????????? - NumHalfwordToRead : number of half-words to read.
* Output???????? : None
* Return???????? : None
*******************************************************************************/
void FSMC_SRAM_ReadBuffer(u16* pBuffer,u32 ReadAddr,u32 NumHalfwordToRead)
{
? for(; NumHalfwordToRead != 0; NumHalfwordToRead--) /* while there is data to read */
? {
??? /* Read a half-word from the memory */
??? *pBuffer++ = *(vu16*) (Bank1_SRAM3_ADDR + ReadAddr);
??? /* Increment the address*/?
??? ReadAddr += 2;
? }?
}
/******************* (C) COPYRIGHT 2008 STMicroelectronics *****END OF FILE****/
?
/***************************************************************
* Function Name? : FSMC_SRAM_WriteHalfWord
* Description??? : Writes a half-word to the SRAM memory.
* Input????????? : - WriteAddr : SRAM memory internal address to write to.
*????????????????? - Data : Data to write.
* Output???????? : None
* Return???????? :
*******************************************************************************/
void FSMC_SRAM_WriteHalfWord(u32 WriteAddr,u16 Data)
{
? //NOR_WRITE(ADDR_SHIFT(0x05555),0x00AA);
?// NOR_WRITE(ADDR_SHIFT(0x02AAA),0x0055);
?// NOR_WRITE(ADDR_SHIFT(0x05555),0x00A0);
? SRAM_WRITE((Bank1_SRAM3_ADDR + WriteAddr),Data);
? //return (FSMC_NOR_GetStatus(Program_Timeout));
}
/******************************************************************************
* Function Name? : FSMC_SRAM_ReadHalfWord
* Description??? : Reads a half-word from the SRAM memory.
* Input????????? : - ReadAddr : NOR memory internal address to read from.
* Output???????? : None
* Return???????? : Half-word read from the SRAM memory
*******************************************************************************/
u16 FSMC_SRAM_ReadHalfWord(u32 ReadAddr)
{
? //NOR_WRITE(ADDR_SHIFT(0x005555),0x00AA);
? //NOR_WRITE(ADDR_SHIFT(0x002AAA),0x0055);?
? //NOR_WRITE((Bank1_NOR2_ADDR + ReadAddr),0x00F0 );
? return (*(vu16 *)((Bank1_SRAM3_ADDR + ReadAddr)));
}
?
?
2.MAIN.C
?
/******************** (C) COPYRIGHT 2008 STMicroelectronics ********************
* File Name????????? : main.c
* Author???????????? : MCD Application Team
* Version??????????? : V2.0.1
* Date?????????????? : 06/13/2008
* Description??????? : Main program body
********************************************************************************
* 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,
* 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 BUFFER_SIZE??????? 0x400
#define WRITE_READ_ADDR??? 0x8000
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;
ErrorStatus HSEStartUpStatus;
u16 TxBuffer[BUFFER_SIZE];
u16 RxBuffer[BUFFER_SIZE];
u32 WriteReadStatus = 0,Index = 0;
/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void NVIC_Configuration(void);
void Fill_Buffer(u16 *pBuffer,u16 BufferLenght,u32 Offset);
/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
* Function Name? : main
* Description??? : Main program.
* Input????????? : None
* Output???????? : None
* Return???????? : None
*******************************************************************************/
int main(void)
{
#ifdef DEBUG
? debug();
#endif
? /* System Clocks Configuration */
? RCC_Configuration();??
? /* NVIC Configuration */
? NVIC_Configuration();
? /* PF.06 and PF.07 config to drive LD1 and LD2 ******************************/
? /* Enable GPIOF clock */
? RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOF,ENABLE);
?
? /* Configure PF.06 and PF.07 as Output push-pull */
? GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
? GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
? GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
? GPIO_Init(GPIOF,&GPIO_InitStructure);
?
? /* Write/read to/from FSMC SRAM memory? *************************************/
? /* Enable the FSMC Clock */
? RCC_AHBPeriphClockCmd(RCC_AHBPeriph_FSMC,ENABLE);
?
? /* Configure FSMC Bank1 NOR/SRAM3 */
? FSMC_SRAM_Init();
? /* Write data to FSMC SRAM memory */
? /* Fill the buffer to send */
? Fill_Buffer(TxBuffer,BUFFER_SIZE,0x3212);
? FSMC_SRAM_WriteBuffer(TxBuffer,WRITE_READ_ADDR,BUFFER_SIZE);
? /* Read data from FSMC SRAM memory */
? FSMC_SRAM_ReadBuffer(RxBuffer,BUFFER_SIZE);?
? /* Read back SRAM memory and check content correctness */??
? for (Index = 0x00; (Index < BUFFER_SIZE) && (WriteReadStatus == 0); Index++)
? {
??? if (RxBuffer[Index] != TxBuffer[Index])
??? {
????? WriteReadStatus = Index + 1;
??? }
? }?
? if (WriteReadStatus == 0)
? {?/* OK */
??? /* Turn on LD1 */
??? GPIO_SetBits(GPIOF,GPIO_Pin_6);
? }
? else
? { /* KO */
??? /* Turn off LD2 */
??? GPIO_SetBits(GPIOF,GPIO_Pin_7);????
? }
? while (1)
? {
? }
}
/*******************************************************************************
* Function Name? : RCC_Configuration
* Description??? : Configures the different system clocks.
* Input????????? : None
* Output???????? : None
* Return???????? : None
*******************************************************************************/
void RCC_Configuration(void)
{??
? /* RCC system reset(for debug purpose) */
? RCC_DeInit();
? /* Enable HSE */
? RCC_HSEConfig(RCC_HSE_ON);
? /* Wait till HSE is ready */
? HSEStartUpStatus = RCC_WaitForHSEStartUp();
? if(HSEStartUpStatus == SUCCESS)
? {
??? /* Enable Prefetch Buffer */
??? FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
??? /* Flash 2 wait state */
??? FLASH_SetLatency(FLASH_Latency_2);
??
??? /* HCLK = SYSCLK */
??? RCC_HCLKConfig(RCC_SYSCLK_Div1);
?
??? /* PCLK2 = HCLK */
??? RCC_PCLK2Config(RCC_HCLK_Div1);
??? /* PCLK1 = HCLK/2 */
??? RCC_PCLK1Config(RCC_HCLK_Div2);
??? /* PLLCLK = 8MHz * 9 = 72 MHz */
??? RCC_PLLConfig(RCC_PLLSource_HSE_Div1,RCC_PLLMul_9);
??? /* Enable PLL */
??? RCC_PLLCmd(ENABLE);
??? /* Wait till PLL is ready */
??? while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
??? {
??? }
??? /* Select PLL as system clock source */
??? RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
??? /* Wait till PLL is used as system clock source */
??? while(RCC_GetSYSCLKSource() != 0x08)
??? {
??? }
? }
}
/*******************************************************************************
* Function Name? : NVIC_Configuration
* Description??? : Configures Vector Table base location.
* Input????????? : None
* Output???????? : None
* Return???????? : None
*******************************************************************************/
void NVIC_Configuration(void)
{
#ifdef? VECT_TAB_RAM?
? /* Set the Vector Table base location at 0x20000000 */
? NVIC_SetVectorTable(NVIC_VectTab_RAM,0x0);
#else? /* VECT_TAB_FLASH? */
? /* Set the Vector Table base location at 0x08000000 */
? NVIC_SetVectorTable(NVIC_VectTab_FLASH,0x0);??
#endif
}
/*******************************************************************************
* Function name : Fill_Buffer
* Description?? : Fill the global buffer
* Input???????? : - pBuffer: pointer on the Buffer to fill
*???????????????? - BufferSize: size of the buffer to fill
*???????????????? - Offset: first value to fill on the Buffer
* Output param? : None
*******************************************************************************/
void Fill_Buffer(u16 *pBuffer,u32 Offset)
{
? u16 IndexTmp = 0;
? /* Put in global buffer same values */
? for (IndexTmp = 0; IndexTmp < BufferLenght; IndexTmp++ )
? {
??? pBuffer[IndexTmp] = IndexTmp + Offset;
? }
}
#ifdef? DEBUG
/*******************************************************************************
* Function Name? : assert_failed
* Description??? : Reports the name of the source file and the source line number
*????????????????? where the assert_param error has occurred.
* Input????????? : - file: pointer to the source file name
*????????????????? - line: assert_param error line source number
* Output???????? : None
* Return???????? : None
*******************************************************************************/
void assert_failed(u8* file,u32 line)
{
? /* User can add his own implementation to report the file name and line number,
???? ex: printf("Wrong parameters value: file %s on line %d/r/n",file,line) */
? /* Infinite loop */
? while (1)
? {
? }
}
#endif
/******************* (C) COPYRIGHT 2008 STMicroelectronics *****END OF FILE****/
来源：http://blog.csdn.net/dainifeixiang/article/details/5539104
