[U-Boot-Users] minimum bdi config to read flash on 85xx

Ben Warren bwarren at qstreams.com
Fri Sep 14 20:43:10 CEST 2007

robert lazarski wrote:
> On 9/12/07, David Hawkins <dwh at ovro.caltech.edu> wrote:
>> Don't move onto anything until you can read the
>> manufacturer ID, you've found a problem, so you
>> need to figure it out here first.
> We have yet to be able to repeat that feat at any other address. We
> can read 0xCAFE from 0xf8000F00 , but only after about a minute after
> a bdi boot. We cannot overwrite 0xf8000F00 , nor can we erase the
> entire chip via the documented sequence. As I said we think we have
> timing issues. Any suggestions? More RTFM? We do have a logic
> analyzer.
Nice progress! Since you have a logic analyzer, you should definitely 
get a sense of the timing, which may or may not reveal anything. You 
have this chip select really slowed down, and it's asynchronous, so 
something would have to really be out of whack.

I'd be more tempted to look elsewhere. What else do you have on the 
local bus? Are other devices isolated via buffers in the same way that 
the Freescale eval boards are? Is the flash VCC looking good? Is the 
reset signal solid?


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