STM32 external sdram strange problem

[lbguan]

Posted on August 12, 2016 at 07:27

STM32 external SDRAM(32bit width,FSMC interface) 16bit and 32bit writing OK,but 8bit writing is not OK, shown below,source file is also attached.

Test Resultsuint8_t  write_buf1[100];write_buf1[0] = 0x01;  //0xC0000000 is 0x01write_buf1[1] = 0x02;  //0xC0000001 is 0x02write_buf1[2] = 0x03;  //0xC0000003(not 0xC0000002) is 0xFF !write_buf1[3] = 0x04;  //0xC0000002 is 0xFF !  write_buf1[4] = 0x05;  //0xC0000004 is 0x05 write_buf1[5] = 0x06;  //0xC0000005 is 0x06 write_buf1[6] = 0x07;  //0xC0000007(not 0xC0000006) is 0xFF !write_buf1[7] = 0x08;  //0xC0000006 is 0xFF !  ......Test ConditionsMCU, STM32F746IGTxSDRAM, Micron MT48LC4M32B2IDE, MDK 5.15where might I go wrong? any advice is greatly appreciated! #sdram-fmc

[troy1818]

Posted on August 13, 2016 at 11:14

Hi,

I would suggest that you revisit the FSMC configuration for the memory chip. Also, take a look at the initiation code for the sdram. Perhaps you can disclose it in this thread ?If you are using ST HAL library it is the structures in FMC_SDRAM_CommandTypeDef, FMC_SDRAM_TimingTypeDef and SDRAM_HandleTypeDef that are of interest.

[Tesla DeLorean]

Posted on August 15, 2016 at 04:25

Is this a standard board or one you created? You might want to double check the wiring of the Byte-Lane signals. Look for shorts or cross-connections.