STM32F429 external SDRAM issue

charles239955 · ‎2016-11-14

Posted on November 14, 2016 at 10:38

Hi All,

I have a custom hardware dev board which includes an SDRAM (AS4C16M16SA), NOR Flash (S29GL128S) and a STM32F429. The schematic for this board is identical to other commercial dev boards that have the same memory configuration.

I am attempting to access the SDRAM through the FMC on the F4. The chip select for the NOR Flash is permanently disabled (set the GPIO pin high).

I have setup a project in IAR 7.8 using the ST example (from Cube) as a base. I have adjusted the timing to match the SDRAM in use although it was almost exactly the same as the example. I am debugging using an ST Link probe.

I am able to repeatedly read/write single values to/from the SDRAM (8/16/32 bits) using the ST library function HAL_SDRAM_Write() - happy days. However when I try and write more than one value sequentially using the HAL_SDRAM_Write() function the micro locks up. I have run the code without the debug probe attached and the result is the same.

Has anyone else seen this behaviour? Any ideas?

Thanks in advance.

slimen · ‎2016-11-17

Posted on November 17, 2016 at 14:20

Hello,

Maybe you should have a look to the Errata Sheet to check if you have the same limitations.

Regards

markus239955_stm1_stmicro_com · ‎2016-11-17

Posted on November 18, 2016 at 07:33

If you generate the initialisation code of the SDRAM controller of the STM32 with CubeMX, do not forget to add the code to configure the initialisation of the SDRAM controller inside of the SDRAM chip. It is not done automatically. Compare the CubeMX generated code with the BSP of an eval-/disco board to see the difference.

Best regards,

Markus.