Am 07.08.2014 um 14:57 schrieb Stefan Tauner:
On Thu, 7 Aug 2014 12:58:23 +0200 The Raven email@example.com wrote:
Can i lower the spi frequency with serprog? Maybe the chip is overclocked?
The datasheet states "10 MHz Max Clock Frequency". AFAIK you are using an Arduino which has a 16 MHz clock, but the maximum SPI frequency the CPU supports is CLK_cpu/2, i.e. 8 MHz, shouldn't be a problem. Anyway, serprog supports an spispeed parameter but the programmer has to support that too (no idea if GNUtoo's code does that).
flashrom -p serprog:dev=/dev/device:baud,spispeed=2M
Or maybe this is a "clone" chip? Not a "real" SST?
Possible in theory, but why would it reply with 0x7fff to RDID commands? I am pretty certain it is an electrical issue on the SPI bus.
I tried another chip and got the same results. :-( The wires are short as possible (8cm incl. serprog/arduino wiring). All other chips work as the should, only this chip give me a wrong reply of "id1 0x5f, id2 0xdf".
Have no clue whats wrong. I give up.