[U-Boot-Users] A question about sdram_init

Stefan Roese stefan.roese at esd-electronics.com
Fri May 14 10:15:47 CEST 2004


Hello Frank!

> Sorry, wrong function name. I've corrected in the second 
> post. The problem 
> happens in cpu/ppc4xx/sdram.c -> sdram_init().

OK. I wrote this code, so here a few comments.

We are using this code on a least 10 different PPC405 boards without any
problems (even with 4 Mbytes of SDRAM).

When you stripped the code to 3 lines only you probably missed those
lines:

	...
	mtsdram0(mem_sdtr1, sdtr1);
	mtsdram0(mem_rtr, rtr);

Some of the sdram regs don't get initialized at all with your code! This
could cause serious problems!

Some further questions:

Why did you change the code in the first place? 

You speak of 8MBytes of SDRAM. Do you have 2 banks each 4MByte? This
code only supports the first bank.

Best regards,
Stefan Roese





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