大家好，STM32单片机FMC接口，初始化为SRAM，使能了异步通信NWAIT功能，同步通信NWAIT禁止，低电平有效，设置为等待周期前一个数据有效。NWAIT接有上拉电阻，所以默认状态高电平。这些配置都配置完毕后，由于NWAIT是高电平，STM32应该是读不到数据的，但是实际上并不影响STM32读到数据，很奇怪，请教一个大家，谢谢大家。        SRAM_HandleTypeDef  CPLD_sram;
        FMC_NORSRAM_TimingTypeDef Timing;
       
        CPLD_sram.Init.NSBank = FMC_NORSRAM_BANK1;
        CPLD_sram.Init.DataAddressMux = FMC_DATA_ADDRESS_MUX_DISABLE;
        CPLD_sram.Init.MemoryType = FMC_MEMORY_TYPE_SRAM;
        CPLD_sram.Init.MemoryDataWidth = FMC_NORSRAM_MEM_BUS_WIDTH_16;
        CPLD_sram.Init.BurstAccessMode = FMC_BURST_ACCESS_MODE_DISABLE;
        CPLD_sram.Init.WaitSignalPolarity = FMC_WAIT_SIGNAL_POLARITY_LOW;  
        CPLD_sram.Init.WaitSignalActive = FMC_WAIT_TIMING_BEFORE_WS;      
        CPLD_sram.Init.WriteOperation = FMC_WRITE_OPERATION_ENABLE;
        CPLD_sram.Init.WaitSignal = FMC_WAIT_SIGNAL_DISABLE;               
        CPLD_sram.Init.ExtendedMode = FMC_EXTENDED_MODE_DISABLE;
        CPLD_sram.Init.AsynchronousWait = FMC_ASYNCHRONOUS_WAIT_ENABLE;
        CPLD_sram.Init.WriteBurst = FMC_WRITE_BURST_DISABLE;
        CPLD_sram.Init.ContinuousClock = FMC_CONTINUOUS_CLOCK_SYNC_ONLY;
        CPLD_sram.Init.WriteFifo = 0;
        CPLD_sram.Init.PageSize = 0;       
        CPLD_sram.Instance = FMC_NORSRAM_DEVICE;
        CPLD_sram.Extended = FMC_NORSRAM_EXTENDED_DEVICE;       
        Timing.AddressSetupTime = 0;
        Timing.AddressHoldTime = 0;
        Timing.DataSetupTime = 3;
        Timing.BusTurnAroundDuration = 1;
        Timing.CLKDivision = 0;
        Timing.DataLatency = 0;
        Timing.AccessMode = FMC_ACCESS_MODE_A;       
        HAL_SRAM_DeInit(&CPLD_sram);
        HAL_SRAM_Init(&CPLD_sram, &Timing, &Timing);