[U-Boot] Mixed 8/16 bits NOR FLASH support

Albert ARIBAUD albert.aribaud at free.fr
Wed Dec 2 11:57:56 CET 2009


Stefan Roese a écrit :

> Hi Albert,

>> In the case of U-boot's CFI detection code, it detects the MX29LV400CB
>> as 16-bit because of its QRY block offset (0x20) and null upper bytes.
>> Then it wants to talk to it using 16-bit wide writes at 16-bit mode
>> offsets, which, in my case, fails.
> 
> Since the CFI driver starts detection in 8bit mode and only switches to 16bit 
> mode (32bit etc.) if this fails, we seem to have a problem with 8bit mode 
> detection of this chip.

All 8-bit mode checks assume the QRY bytes are at addresses 0x10, 0x11, 
0x12 etc. So they fail too, since a mixed-mode chip outputs a word-mode 
QRY always, at addresses 0xx20, 0x22, 0x24 etc.

Amicalement,
-- 
Albert.


More information about the U-Boot mailing list