FSMC读8位内存出错，请教大家

只看该作者 · 2019-12-24 10:52

本帖最后由 static 于 2019-12-24 11:05 编辑

大家好，使用FSMC经验不足，现使用FSMC读取8bit 外部RAM，读到的数据有错位且只有第一次是正确的的，求教大家，谢谢大家帮忙指正。

如上图： CE接NE2，所以CS地址空间是：BANK2：6400 0000 --- 67ff ffff ;
FSMC 配置如下(根据官方代码修改)：

读数据：

uint8_t data = 0x55 ;
  /* Write data to the SRAM memory */
  for(uwIndex = 0; uwIndex < 3; uwIndex++)
  {
*(__IO uint8_t *)(0x64000000 + uwIndex) = data;
printf ( "FSMC read buffer[%d] fill = %x , \r\n" , uwIndex , data );
  }

  /* Read back data from the SRAM memory */
  for(uwIndex = 0; uwIndex < 3; uwIndex++)
  {
aRxBuffer[uwIndex] = *(__IO uint8_t *)(0x64000000 +  uwIndex);
printf ( "FSMC read buffer[%d] READ = %x , \r\n" , uwIndex , aRxBuffer[uwIndex] );
  }

uint8_t volatile *Test1,*Test2;
Test1=(uint8_t *)0x64000100;
*Test1++=0x99;
printf ( "FSMC read buffer3 = %x , \r\n" , *(volatile uint8_t *)0x64000100 );
printf ( "FSMC read buffer3 = %x , \r\n" , *(volatile uint8_t *)0x64000100 );

打印出数据为：
FSMC read buffer[0] fill = 55 ,
FSMC read buffer[1] fill = 55 ,
FSMC read buffer[2] fill = 55 ,
FSMC read buffer[0] READ = 5 ,
FSMC read buffer[1] READ = 5 ,
FSMC read buffer[2] READ = 5 ,
FSMC read buffer3 = 99 ,
FSMC read buffer3 = 1 ,

请问大家问题出在哪里？始终没搞懂