Using SDRAM and NOR Flash

[ducommun]

Posted on May 05, 2015 at 09:27

I have a simple project running on my STM324x9IEval Kit using external SDRAM and NOR Flash.

The project run correctly when a use only SDRAM, &sharpdefine DATA_IN_ExtSDRAM is uncommented in system_stm32f4xx.c and my vars are located correctly in SDRAM.The project run correctly when I use NOR Flash without external SDRAM.But when I enable the external SDRAM and use the NOR Flash, the software crash when I try to erase or program the NOR Flash. The init and read are working.When I tell the software crash, the debugguer lose the connection with the target and I can't see what is happening.I have tryed to use external SRAM and NOR Flash, and the code work as expected.Do you have any idea of the cause of this issue which is happening only when external SDRAM and NOR flash erase or write operation is executed ?Thanks #sdram-nor

[stm322399]

Posted on May 05, 2015 at 10:00

Christophe,

this is a known bug of F4 silicon (see F4 errata). Only the very latest MCU revision (beginning of this year) are fixed. It is likely that your eval kit has a faulty MCU. There are no workaround (except not using NOR and SDRAM simultaneously, of course !).

[ducommun]

Posted on May 06, 2015 at 10:05

Ok thanks for your answer.

It seem's to be section 2.9.7 in the errata sheet.I have checked the revision on my F429, and it is a revision 1 and it has been fixed in revision 3.