On Sat, 19 Jun 2010 14:04:21 -0700 audiohacked at gmail.com (Sean Nelson) wrote:
On 5/28/10 9:48 AM, fritz wrote:
However, the chip I wanted to program - Am29F040B - I could NOT detect.
I'll spare you the in-depth story of the past twelve hours I've spent working on it.
The summary: Flashrom (from svn) would detect the other chips using addresses 0x5555, 0x2AAA, 0x5555 Flashrom (from svn) would try to detect the Am29F040 using addresses 0x0555, 0x02AA, 0x0555 - which is not according to the datasheet.
The Problem is the Am29F040B uses 0x2AA variant, but the Am29F040 uses 0x2AAA. What AMD/Spansion did was change the command addresses without changing the chip ids. Sadly there's no way to distinguish between the two.
Seems like they have done that between Am29F010 and Am29F010A as well (cf. "Not detecting Am29F010 using 3Com PCI nic" by Ignatius Grippa)...
Actually, there is of course a way to distinguish them: probe once with FEATURE_ADDR_2AA and once with FEATURE_ADDR_2AAA :) I'll try to get Ignatius to test this...