Re: Cool Road Runner (was CFA as Ide.)

["Richard A. Smith" <rsmith@bitworks.com>]

On Mon, 02 Apr 2001 21:50:59 +0100, Adrian Cox wrote:

>> IIRC SanDisk was the original people to come out with IDE CFA and everyone
>> else just copied them.  I have the SanDisk datasheets that I can send you
>> if you need them to verify stuff.  I believe that if you verify it with 
>> the SanDisk then all the other MFG's should work as well.
>
>If only. In my limited experience SanDisk cards have been the most 
>tolerant. I suspect that Sandisk actually implement the full range of 
>timings documented in the spec, and nobody else bothers.
>
>This isn't normally a problem on PC hardware, but if you try to 
>implement an interface to talk to a CF card in an embedded system you 
>find this out.

Hmmm... most of our embedded systems are based on a PC somehow either via a processor card or  
an actual PC system that we design so perhaps I have't stressed the limits yet.

We do actually use SST (Silcon Storage Technolog) CF's as well and they seem to function just 
identical to the SanDisk but not quite as robust... I have had several of the SST's develope 
a problem in the partition table and as thus the just error when you try to mount them.
Several people on the liunx-embedded list also have similar experiences.

That seems to follow your observations...

Will it be worth while for you if I break out the scope and examine how our CF's handle the 
PDIAG signal or can we just go on faith that they do indeed work as expected?


--
Richard A. Smith                         Bitworks, Inc.               
rsmith@bitworks.com               501.846.5777                        
Sr. Design Engineer        http://www.bitworks.com