[LinuxBIOS] different versions of the GA-M57SLI-S4 (PLCC vs SPI)

Peter Stuge peter at stuge.se
Sat Sep 1 19:57:18 CEST 2007

On Thu, Aug 30, 2007 at 08:09:20AM -0400, Ward Vandewege wrote:
> On Thu, Aug 30, 2007 at 12:35:47PM +0100, Chris Lingard wrote:
> > They say the socket that I got is wrong, (PLCC32).
> > 
> > Will the SST 49LF040 be wrong too.
> Most likely if your board is not plcc.

Yes - then neither socket nor flash chip can be mounted.

> > Is the modification now wrong?
> ST, can you chime in here?

Hard to tell without testing. I could give it a go if I had a board.
But, someone please send a high-res photo of this part of the board:
http://stuge.se/m57sli_spi_mod_area.jpg so that we can have a look at
the traces. Please take the photo from straight above the board so
that the black PCIe sockets do not obscure any traces or components.

There is also the problem of documentation re. SPI flash programming
at least on the MCP55; AFAIK there's only documentation for SPI
flashing on Intel southbridges.

Once we figure out the hardware, it will still be neccessary to
reboot into DOS/Windows to flash either chip. :(

Re sockets I haven't seen anything that would work well for SOIC.
(SOIC and PLCC are packages, SPI and LPC the bus interface.)

One easy trick is to attach a clothespin-like clip (Pomona SOIC CLIP
5250) on top of the first flash chip and then connect different flash
chips to that clip. This works if the soldered-on flash chip has a
HOLD# pin, which seems to be common.

A problem with the clip is that it can come off by accident or worse
have a glitch in the connection (unlikely, but still) which would
cause the soldered-on chip to be overwritten by mistake and bricking
the board if the BIOS image was bad. This can be worked around by
flashing the factory BIOS onto the clip flash chip and then only
working with LB using the soldered-on flash chip. :)

Connecting a second flash chip to the clip is very simple
electrically, but a bit tricky mechanically since the upper contacts
on the clip move when the clip is detached/attached. The most durable
method would be AMPMODU contacts for the second row, but just
soldering wires should work too. A small adapter board is needed for
the SOIC flash chip as well, since the flash chip has .05" pin
spacing while the test clip has .1" pin spacing. Either just strip
board or a ready made SOIC adapter board such as the Sunhayato Corp
PC BOARD ICB-010. (non-RoHS)


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