RT-Thread 基于QSPI驱动LY68L6400-SRAM

前言

使用的是RTThread 标准版，主控是STM32H743，SRAM是LY68L6400，使用QSPI

QSPI和SPI的区别

个人理解最大的区别就是SPI是串行，数据输出，而QSPI跟像并行输出，比如从单数据线的SPI到4数据线的QSPI。

LY68L6400

SRAM的QSPI的波形图，注意这个读取等待周期，十分重要。也是区别于SPI的地方

在KCONFIG中添加开启QSPI

	menuconfig BSP_USING_QSPI
        bool "Enable QSPI BUS"
        default n
        select RT_USING_QSPI
        select RT_USING_SPI      

RTT中的QSPI的读取时 需要配置的一些参数

RTT中的QSPI的写入时 需要配置的一些参数，和读取不同的就是命令码，空闲等待周期是为0

void qspi_ly68_write(rt_uint32_t waddr,rt_uint8_t *wdata,rt_uint32_t size)
{
		struct rt_qspi_device *qspi_dev_ly68 = RT_NULL;
		struct rt_qspi_message message;
		rt_err_t result = RT_EOK;
	
		qspi_dev_ly68 = (struct rt_qspi_device *)rt_device_find(QSPI_DEVICE_NAME);
    if(qspi_dev_ly68 == RT_NULL){
        rt_kprintf("qspi sample run failed! can't find %s device!\n", QSPI_DEVICE_NAME);
    }
		else
		{
        message.parent.send_buf = wdata;
        message.parent.recv_buf = RT_NULL;
        message.parent.length = size;
        message.parent.next = RT_NULL;
        message.parent.cs_take = 1;
        message.parent.cs_release = 1;
        message.instruction.content = 0X38;
        message.instruction.qspi_lines = 1;
        message.address.content = waddr;
        message.address.size = 24;
        message.address.qspi_lines = 4;
        message.dummy_cycles = 0;
        message.qspi_data_lines = 4;
        result = rt_qspi_transfer_message(qspi_dev_ly68, &message);
			
		}
}

void qspi_ly68_read(rt_uint32_t raddr,rt_uint32_t size)
{
		struct rt_qspi_device *qspi_dev_ly68 = RT_NULL;
		struct rt_qspi_message message;
		rt_err_t result = RT_EOK;
		rt_uint32_t i;
	
		qspi_dev_ly68 = (struct rt_qspi_device *)rt_device_find(QSPI_DEVICE_NAME);
    if(qspi_dev_ly68 == RT_NULL){
        rt_kprintf("qspi sample run failed! can't find %s device!\n", QSPI_DEVICE_NAME);
    }
		else
		{

        message.parent.send_buf = RT_NULL;
        message.parent.recv_buf = qrData;
        message.parent.length = size;
        message.parent.next = RT_NULL;
        message.parent.cs_take = 1;
        message.parent.cs_release = 1;
        message.instruction.content = 0XEB;
        message.instruction.qspi_lines = 1;
        message.address.content = raddr;
        message.address.size = 24;
        message.address.qspi_lines = 4;
        message.dummy_cycles = 6;
        message.qspi_data_lines = 4;
        rt_qspi_transfer_message(qspi_dev_ly68, &message);

				


		}
}

一些问题

使用QSPId DMA 的话会遇到一个问题，就是drv_qspi.c中的DMA写的不对
具体如下图，在使用STM32H7的时，drv_qspi.c中的参数还是hdma，但是实际上H7的文件中定义的是hmdma，在其他系列还能用，在H7上要用DMA是需要修改的。