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FMC bus on STM32F427

cpinkstone2
Associate II
Posted on February 14, 2014 at 11:46

Dear All,

I�m currently trying to get a new board up and running.

I keep ending up in the Hardfault Handler with an undefined instruction.

Seems that the stack pointer is somehow pointing to somewhere out of the stack space.

 

My board uses an STM32F427II Rev Y Silicon.

I have on the FMC bus:-  SDRAM on bank1 (16bit wide bus)

        With some  NOR Flash (16bit wide bus)  

and also a display controller for TFT (SSD1963) mapped as SRAM.

The code has a problem somewhere in the emWin routines, which I don't have the source for.

I'm concerned that I may be suffering from the following in the errata sheet.  

 

2.8.7 FMC dynamic and static bank switching

Description

The dynamic and static banks cannot be accessed concurrently.

Workaround

Do not use dynamic and static banks at the same time. The SDRAM device must be in selfrefresh

before switching to the static memory mapped on the NOR/PSRAM or NAND/PCCard

controller. Before switching from static memory to SDRAM, issue a Normal command

to wake-up the device from self-refresh mode.

This limitation will be fixed in next silicon revision.

 

I�m using the SDRAM as memory / frame buffer for emWin so don�t have total control on when it will read from the external Flash on FMC and write out to the display?

Has anyone got a system up and running with SDRAM and a display controller on the FMC bus??

Thanks for any help given. 

#stm32f427-fmc-sdram
2 REPLIES 2
stm322399
Senior
Posted on April 18, 2014 at 17:11

I'am afraid I'am facing the same issue.

Did you finally find a solution for your problem ?

jasonj2
Associate II
Posted on April 20, 2014 at 06:33

I may have the same problem. I am using Rev.Y silicon too.  My board have a 16bit SDRAM connected to the second SDRAM BANK, a NAND Flash, and a FPGA mapped to NOR/PSRAM bank. But the workaround stated in 

2.8.7 FMC dynamic and static bank switching does not applies to me as I cannot determine when will SDRAM will be accessed.

When will a new silicon will be available on market? I cannot choose the revision as I ordered the chip from DIGIKEY. How can I ensure the chip I got have all the FMC related problems fixed?