mutable 发表于 2021-12-17 15:03

FSMC非复用方式控制NOR Flash的程序设计

根据配置的接口电路配置GPIO初始化程序与FSMC初始化程序。
void FSMC_NOR_Init(void)
{
    FSMC_InitTypeDefFSMC_InitStructure;
    FSMC_NORSRAM_Bank_InitTypeDefFSMC_BankInitStructure;

    FSMC_NORSRAM_BankStructInit(&FSMC_BankInitStructure);
    FSMC_NORSRAMStructInit(&FSMC_InitStructure);
    RCC_AHB3PeriphClockCmd(RCC_AHB3ENR_FSMC, ENABLE);

    FSMC_BankInitStructure.FSMC_SMReadPipe    = 0;
    FSMC_BankInitStructure.FSMC_ReadyMode   = 0;
    FSMC_BankInitStructure.FSMC_WritePeriod   = 15;
    FSMC_BankInitStructure.FSMC_WriteHoldTime = 3;
    FSMC_BankInitStructure.FSMC_AddrSetTime   = 3;
    FSMC_BankInitStructure.FSMC_ReadPeriod    = 15;
    FSMC_BankInitStructure.FSMC_DataWidth   = FSMC_DataWidth_16bits;
    FSMC_NORSRAM_Bank_Init(&FSMC_BankInitStructure, \
    FSMC_NORSRAM_BANK1);

    FSMC_InitStructure.FSMC_Mode = FSMC_Mode_NorFlash;
    FSMC_InitStructure.FSMC_TimingRegSelect = FSMC_TimingRegSelect_0;
    FSMC_InitStructure.FSMC_MemSize = FSMC_MemSize_64MB;
    FSMC_InitStructure.FSMC_MemType = FSMC_MemType_FLASH;
    FSMC_InitStructure.FSMC_AddrDataMode = FSMC_AddrDataDeMUX;
    FSMC_NORSRAMInit(&FSMC_InitStructure);
}GPIO初始化
void FSMC_GPIO_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_StructInit(&GPIO_InitStructure);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBENR_GPIOB | RCC_AHBENR_GPIOC | \
    RCC_AHBENR_GPIOA | RCC_AHBENR_GPIOD | RCC_AHBENR_GPIOE | \
    RCC_AHBENR_GPIOF | RCC_AHBENR_GPIOG, ENABLE);

    GPIO_PinAFConfig(GPIOD, GPIO_PinSource4, GPIO_AF_12);//NOE
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource5, GPIO_AF_12);//NWE
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource6, GPIO_AF_12);//NWAIT
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource11, GPIO_AF_12); //A16
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource12, GPIO_AF_12); //A17
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource13, GPIO_AF_12); //A18
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource14, GPIO_AF_12); //D0
    GPIO_PinAFConfig(GPIOD, GPIO_PinSource15, GPIO_AF_12); //D1
    //省略部分代码
    GPIO_PinAFConfig(GPIOF, GPIO_PinSource0, GPIO_AF_12);//A0
    GPIO_PinAFConfig(GPIOF, GPIO_PinSource1, GPIO_AF_12);//A1
    GPIO_PinAFConfig(GPIOF, GPIO_PinSource2, GPIO_AF_12);//A2
    GPIO_PinAFConfig(GPIOF, GPIO_PinSource3, GPIO_AF_12);//A3
    //省略部分代码
    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_All;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_6;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_FLOATING;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    //省略部分代码

}从选择的片选信号与FSMC外扩存储映像空间可以得出Bank2地址为0x64000000,使用该地址作为读写外部NOR Flash的基地址。
#define NOR_FLASH_START_ADDR       ((u32)0x64000000)
#define NOR_FLASH_END_ADDR         ((u32)0x67FFFFFF)
//读一个半字
u16 FSMC_NOR_ReadHalfWord(u32 ReadAddr)
{
    NOR_WRITE(ADDR_SHIFT(0x00555), 0x00AA);
    NOR_WRITE(ADDR_SHIFT(0x002AA), 0x0055);
    NOR_WRITE((NOR_FLASH_START_ADDR + ReadAddr), 0x00F0 );
/* exit autoselect (write reset command) */
    return (*(vu16*)((NOR_FLASH_START_ADDR + ReadAddr)));
}
//连续读一块半字数据
void FSMC_NOR_ReadBuffer(u16* pBuffer, u32 ReadAddr, u32 NumHalfwordToRead)
{
    NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
    NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
    NOR_WRITE((NOR_FLASH_START_ADDR + ReadAddr), 0x00F0);
/* exit autoselect (write reset command) */
    for(; NumHalfwordToRead != 0x00; NumHalfwordToRead--) {
      // Read a Halfword from the NOR
      *pBuffer++ = *(vu16*)((NOR_FLASH_START_ADDR + ReadAddr));
      ReadAddr = ReadAddr + 2;
    }
}读写外部NOR Flash与读写外部SRAM的操作,地址寻址方式是一样的,但NOR Flash的写数据有较大的不同。
以单个Word编程为例,如下为写单个Word的流程图与实现代码:NOR_Status FSMC_NOR_WriteHalfWord(u32 WriteAddr, u16 Data)
{
    NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
    NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
    NOR_WRITE(ADDR_SHIFT(0x0555), 0x00A0);
    NOR_WRITE((NOR_FLASH_START_ADDR + WriteAddr), Data);

    return (FSMC_NOR_GetStatus(Program_Timeout));
}通过MindMotion的官网下载MM32F3270 lib_Samples:https://www.mindmotion.com.cn/products/mm32mcu/mm32f/mm32f_mainstream/mm32f3270/ 工程路径如下:~MM32F327x_Samples\LibSamples\FSMC\FSMC_NOR\可以看到详细的样例与功能操作。








七毛钱 发表于 2021-12-17 16:44

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