访问手机版页面
你的位置:老古开发网 > STM32单片机的FSMC > 正文  
STM32单片机FSMC模块的应用
内容导读:

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;

}

}

标签:FSMC模块,STM32单片机,sram,
来源:工程师周亮 作者:lhl545545 时间:2019/1/14 14:58:00
相关阅读
推荐阅读
阅读排行
最近更新
商品推荐