[U-Boot] Flash Not Erased for M29W128GL

[Ramesh K Khokhani]

Hi Friends,

I am having problem with 16MB M29W128GL Flash. I am getting Flash Not Erased when i try to use saveenv command at u-boot command prompt.

I have tried manually Byte by Byte wise writing to NOR Flash location so for that i have use following command and getting 2 same byte write on consecutive location.

And when i have try to write word using mw.w then it writes correct.

Before use command:

-> md 0x50000

00050000: ffffffff ffffffff ffffffff ffffffff    ................
00050010: ffffffff ffffffff ffffffff ffffffff    ................
00050020: ffffffff ffffffff ffffffff ffffffff    ................
00050030: ffffffff ffffffff ffffffff ffffffff    ................
00050040: ffffffff ffffffff ffffffff ffffffff    ................
00050050: ffffffff ffffffff ffffffff ffffffff    ................
00050060: ffffffff ffffffff ffffffff ffffffff    ................
00050070: ffffffff ffffffff ffffffff ffffffff    ................
00050080: ffffffff ffffffff ffffffff ffffffff    ................
00050090: ffffffff ffffffff ffffffff ffffffff    ................
000500a0: ffffffff ffffffff ffffffff ffffffff    ................
000500b0: ffffffff ffffffff ffffffff ffffffff    ................
000500c0: ffffffff ffffffff ffffffff ffffffff    ................
000500d0: ffffffff ffffffff ffffffff ffffffff    ................
000500e0: ffffffff ffffffff ffffffff ffffffff    ................
000500f0: ffffffff ffffffff ffffffff ffffffff    ................

After use command: (Here i have try to write 0x12 on 0x50000 location but it writes two same bytes on 0x50000 & 0x50001)

-> mw.b 0x?50?aaa 0xaa

-> mw.b 0x50554 0x55

-> mw.b 0x50aaa 0xa0

-> mw.b 0x50000 0x12

-> md 0x50000

00050000: 1212ffff ffffffff ffffffff ffffffff    ................
00050010: ffffffff ffffffff ffffffff ffffffff    ................
00050020: ffffffff ffffffff ffffffff ffffffff    ................
00050030: ffffffff ffffffff ffffffff ffffffff    ................
00050040: ffffffff ffffffff ffffffff ffffffff    ................
00050050: ffffffff ffffffff ffffffff ffffffff    ................
00050060: ffffffff ffffffff ffffffff ffffffff    ................
00050070: ffffffff ffffffff ffffffff ffffffff    ................
00050080: ffffffff ffffffff ffffffff ffffffff    ................
00050090: ffffffff ffffffff ffffffff ffffffff    ................
000500a0: ffffffff ffffffff ffffffff ffffffff    ................
000500b0: ffffffff ffffffff ffffffff ffffffff    ................
000500c0: ffffffff ffffffff ffffffff ffffffff    ................
000500d0: ffffffff ffffffff ffffffff ffffffff    ................
000500e0: ffffffff ffffffff ffffffff ffffffff    ................
000500f0: ffffffff ffffffff ffffffff ffffffff    ................

When try to write word using mw.w then it writes correct:

-> md? ?w.w 0x50?aaa 0xaa

-> mw.w 0x50554 0x55

-> mw.w 0x50aaa ??xa0? ?

-> mw.w 0x500?10 0x1234

-> md 50000

00050000: 1212ffff ffffffff ffffffff ffffffff    ................
00050010: 1234ffff ffffffff ffffffff ffffffff    .4..............
00050020: ffffffff ffffffff ffffffff ffffffff    ................
00050030: ffffffff ffffffff ffffffff ffffffff    ................
00050040: ffffffff ffffffff ffffffff ffffffff    ................
00050050: ffffffff ffffffff ffffffff ffffffff    ................
00050060: ffffffff ffffffff ffffffff ffffffff    ................
00050070: ffffffff ffffffff ffffffff ffffffff    ................
00050080: ffffffff ffffffff ffffffff ffffffff    ................
00050090: ffffffff ffffffff ffffffff ffffffff    ................
000500a0: ffffffff ffffffff ffffffff ffffffff    ................
000500b0: ffffffff ffffffff ffffffff ffffffff    ................
000500c0: ffffffff ffffffff ffffffff ffffffff    ................
000500d0: ffffffff ffffffff ffffffff ffffffff    ................
000500e0: ffffffff ffffffff ffffffff ffffffff    ................
000500f0: ffffffff ffffffff ffffffff ffffffff    ................


So what may be problem?

Internally it uses following command (8bit x b bit). Is it problem? it should be 16bit x 8 bit?

fwc addr 00040aaa cmd aa aa 8bit x 8 bit
fwc addr 00040554 cmd 55 55 8bit x 8 bit
fwc addr 00040aaa cmd a0 a0 8bit x 8 bit


Thanks & Warm Regards,

Ramesh Khokhani
Senior Software Engineer

[X]

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 ramesh.khokhani at igatepatni.com

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