STM32使用FSMC控制sram例程
一、基本概念
1.與非總線復(fù)用的16位SRAM接口
FSMC配置
SRAM存儲器和NOR閃存存儲器共用相同的FSMC存儲塊，所用的協(xié)議依不同的存儲器類型而有所不同。
控制SRAM存儲器，F(xiàn)SMC應(yīng)該具有下述功能：
●
使用或禁止地址/數(shù)據(jù)總線的復(fù)用功能。
●
選擇所用的存儲器類型：NOR閃存、SRAM或PSRAM。
●
定義外部存儲器的數(shù)據(jù)總線寬度：8或16位。
●
使用或關(guān)閉擴(kuò)展模式：擴(kuò)展模式用于訪問那些具有不同讀寫操作時(shí)序的存儲器。
正如配置NOR閃存存儲器一樣，用戶必須按照SRAM存儲器的數(shù)據(jù)手冊給出的時(shí)序數(shù)據(jù)，計(jì)算和設(shè)置下列參數(shù)：
●
ADDSET：地址建立時(shí)間
●
ADDHOLD：地址保持時(shí)間
●
DATAST：數(shù)據(jù)建立時(shí)間
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;
}
}
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