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STM32单片机FSMC模块的应用

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        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;

        }

        }

               
                                

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