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128Mbit SDRAM Configuration

Question asked by clambake on Feb 6, 2015
Latest reply on Feb 9, 2015 by clambake
I'm developing a prototype using STM32F4 - to start a first prototype I started to write the software for the STM32F429I-DISCO board. I used clive's init code to drive the 64Mbit SDRAM onboard - it works like a charm. Now on the prototype I will need 128Mbit so I had a professional de-solder the original memory chip and exchanged it for a 128Mbit Type: AS4C8M16S.

Both chips are pin-compatible and the only differences I can spot are concerning timing and adressing. This chips has 9 Column Adress lines while the other had only 8.

The significant change was:
FMC_Bank5_6->SDCR[0] = 0x00002800;
to
FMC_Bank5_6->SDCR[0] = 0x00002801;

When I run the application the memory is configured and I get into main but then it seems to crash. In my memory view I can see some (weird) values in the memory. How do I have to adjust the timing to get this RAM to work?

Thanks in advance.

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