AW: DOC vs. IDE

[Richard A. Smith]

On Thu, 24 Oct 2002 00:42:50 -0400, Christopher Bergeron wrote:

> 
> All other indications of CompactFlash are that it's a realiable medium
> (unless you can document otherwise).  I will provide documentation to

Well I don't know that I can "document" but I've had numerious
problems with CF devices.  I've got 5 seperate CFs with Sector 0 CRC
problems.  3 of them are SanDisk but I also have 
2 from SST.  They are various sizes.

This topic has come up on the Linux-embedded list as well.  Others
have experienced the same type of issues we have.

I've spoken with an app engineer at SanDisk and his explaniation was
under certian conditions, like say if your 5V power glitches.  The
internal write state machine gets confused/reset or whatever and it
ends up munging sector 0.  After which the CF won't work in any OS
(including Linux) because it throws and error reading the partition
table.

The SanDisk guy told me I sould be able to recover sector 0 by
writing all zeros to it which will reset the crc but I haven't been
able to find an application that is 1) Freeware and 2) Will do raw
sector writes.

--
Richard A. Smith                         Bitworks, Inc.               
rsmith at bitworks.com               479.846.5777 x104                        
Sr. Design Engineer        http://www.bitworks.com