使用SPI接口读写铁电FM25CL64B失败

发布于 2022-06-06 15:14:52 浏览：591 订阅该版

使用铁电存储器FM25CL64B，通过SPI接口读写数据，

```c
memset(send_buff,0x00,sizeof(send_buff));
		memset(recv_buff,0x00,sizeof(recv_buff));
        send_buff[0] = FRAM_READ; // 1--start up bit
		send_buff[1] = 0x01;
        send_buff[2] = 0x00;
		send_buff[9]=0x05;
        msg.send_buf   = send_buff;
        msg.recv_buf   = recv_buff;
        msg.length     = 13;
        msg.cs_take    = 1;
        msg.cs_release = 1;
        msg.next = NULL;

rt_kprintf("rt_spi_transfer_message1\n");
        rt_spi_transfer_message(spi_device1, &msg);
        rt_kprintf("rt_spi_transfer_message2\n");   
		rt_pin_write(FRAM_CS, PIN_HIGH);//FRAM_CS =1;
		for(int i=0;i<13;i++)
		{
			rt_kprintf("[%d]==%d,",i,recv_buff[i]);			
		}
		rt_kprintf("-----------------------------------------\n");
		
		send_buff[0] = FRAM_WRITE; // 1--start up bit
        send_buff[1] = (write_addr>>8)&0xff;
        send_buff[2] = write_addr&0xff;
        msg.send_buf   = send_buff;
        msg.recv_buf   = recv_buff;
        msg.length     = 3;
        msg.cs_take    = 1;
        msg.cs_release = 1;
        msg.next = NULL;
        rt_spi_transfer_message(spi_device1, &msg);
```
  运行之后的打印BUFFER全是4095.

3 个回答

aozima 2022-06-06

调网络不抓包，调I2C等时序不上逻辑分析仪，就像电工不用万用表！多用整理的好的文字，比截图更省流量，还能在整理过程中思考。

男生111 2022-06-07

拒绝白嫖，拒绝键盘侠！

我做了一下修改，其中的send_buff[3]=0x05;我是写一个字节给FRAM，字节的内容是05，最后的输出内存打印是255
我是缺少写使能吗？
```c
memset(send_buff,0x01,sizeof(send_buff));
		memset(recv_buff,0x00,sizeof(recv_buff));
				
		send_buff[0] = FRAM_WRITE; // 1--start up bit 0x02
        send_buff[1] = 0x00;//(write_addr>>8)&0xff;
        send_buff[2] = 0x00;//write_addr&0xff;
		send_buff[3]=0x05;
        msg.send_buf   = send_buff;
        msg.recv_buf   = recv_buff;
        msg.length     = 4;
        msg.cs_take    = 1;
        msg.cs_release = 1;
        msg.next = NULL;
		
		rt_spi_transfer_message(spi_device1, &msg);
		
		for(int i=0;i<13;i++)
		{
			rt_kprintf("[%d]==%d,",i,recv_buff[i]);			
		}
		rt_kprintf("-----------------------------------------\n");
		
		send_buff[0] = FRAM_READ; // 1--start up bit 0x03
		send_buff[1] = 0x01;
        send_buff[2] = 0x00;		
        msg.send_buf   = send_buff;
        msg.recv_buf   = recv_buff;
        msg.length     = 3;
        msg.cs_take    = 1;
        msg.cs_release = 1;
        msg.next = NULL;

rt_kprintf("rt_spi_transfer_message1\n");
        rt_spi_transfer_message(spi_device1, &msg);
        rt_kprintf("rt_spi_transfer_message2\n");   
		//rt_pin_write(FRAM_CS, PIN_HIGH);//FRAM_CS =1;
		for(int i=0;i<13;i++)
		{
			rt_kprintf("[%d]==%d,",i,recv_buff[i]);			
		}
		rt_kprintf("-----------------------------------------\n");
```

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kid 2022-06-07

这家伙很懒，什么也没写！

男生111 2022-06-07

拒绝白嫖，拒绝键盘侠！

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梅江松子 2022-06-07

这家伙很懒，什么也没写！

```c
static rt_size_t _fram_write(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
{
    struct rt_spi_device *fram = RT_NULL;
    rt_err_t ret = RT_EOK;
    uint8_t *rxcheck = NULL;
    uint8_t txdata[4] = {0};

ret = _fram_mem_size_check(pos, size);
    if (ret != RT_EOK)
    {
        return ret;
    }

fram = (struct rt_spi_device *)rt_device_find(framname);
    txdata[0] = WREN;

rt_spi_send(fram, txdata, 1);
    txdata[0] = WRMD;
    txdata[1] = (pos & 0xff00) >> 8;
    txdata[2] = pos & 0xff;

ret = rt_spi_send_then_send(fram, txdata, 3, buffer, size * FRAM_BLOCK_SIZE);
    rt_thread_delay(5);
    txdata[0] = WRDI;
    rt_spi_send(fram, txdata, 1); /* disable write */

if (ret != RT_EOK)
    {

log_e("write fail\n");
        return 0;
    }
    rxcheck = (uint8_t *)rt_malloc(size);
    _fram_read(dev, pos, rxcheck, size);
    if (rt_memcmp(buffer, rxcheck, size))
    {
        rt_free(rxcheck);

log_e("write fail read!=write\n");
        return 0;
    }
    rt_free(rxcheck);

return size;
}
```

如图所示
```c
    fram = (struct rt_spi_device *)rt_device_find(framname);
    txdata[0] = WREN;

rt_spi_send(fram, txdata, 1);
    txdata[0] = WRMD;
    txdata[1] = (pos & 0xff00) >> 8;
    txdata[2] = pos & 0xff;

ret = rt_spi_send_then_send(fram, txdata, 3, buffer, size * FRAM_BLOCK_SIZE);
    rt_thread_delay(5);
    txdata[0] = WRDI;
    rt_spi_send(fram, txdata, 1); /* disable write */
```
写指令分包发试试  我这用的也是FM25系列的铁电