bios compax sr2020nx flash

Bus Pirate support for the Flashrom project

bios compax sr2020nx flash

Postby simonsimons34 » Wed Jan 02, 2013 2:33 am

Okay so the chip inside this PC is the PM49FL004T-33JCE 32 pin with square design. Its designed by PMC and is towards the front of the board. Below is what I've found. Documentation is easily found at Google
Last edited by simonsimons34 on Fri Jan 04, 2013 2:49 am, edited 1 time in total.
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Re: bios compax sr2020nx flash

Postby simonsimons34 » Fri Jan 04, 2013 2:37 am

Okay, so far looking through the chip ports SPI write with flashrom should work if I get the chip connected properly. Im turing this thread into documentation on my journey in fixing this motherboard

I have taken the chip data sheet and found

vcc to 3v3
gnd to gnd
clk to clk


but now I have to look deeper, as
CS, MISO, and MOSI are all not documented there. Im not even sure if there on the chip at all, but hey if the chip is able to be programed at all the bus pirate should be able to do it.


EDIT (Before I posted, so not really an edit)
but it looks like there are some descriptions of the posts
WIE is the write enabled post
NC is well what I expected, no connection
clk Is clock
rst is reset
then there is a mode set, or IC. It has to be set when the chip is powered on, and sets whether its High or low pull.

Io [7:0] is what does reading and writing (I think that's what im going to want)

So that's what ive found for the night going to see what others think about the different post possibilities and ask around some people who do these kinds of things for a living
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Re: bios compax sr2020nx flash

Postby ian » Wed Jan 09, 2013 5:38 am

This sounds like a parallel flash chip, though the mode pin may set it to a serial mode. Does it look like IO 0:7 are wired and traced on the circuit board?

You best bet might be to ping the flashrom guys, they know about everything there is to know about motherboard ROM chips.
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Re: bios compax sr2020nx flash

Postby simonsimons34 » Wed Jan 09, 2013 6:37 am

I may head over to the flashrom site once I give up on the tinkering aspect. What its looking like is only one of the io ports is traced out, making me think with power it could be sent reset and then mode command as well. Thanks for the.help too @ian. I will be doing a full write up as I go as well as a wrap up when I fix it

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