mtd: looking for serial flash storage

Brendan J Simon brendan.simon at
Tue Oct 9 03:00:36 EDT 2001

David Woodhouse wrote:

>hamishl at said:
>>You need 13 address lines for a DoC (A0..A12). 
>That's only for backwards-compatibility with the DiskOnChip1000 sockets.
>You should be able to omit half of them - just make sure you have A11 and
>A12 connected, and also the bottom six lines. 
>Take a look at the addresses in include/linux/mtd/doc2000.h and observe 
>that we never address the chip such that (addr & 0x7c0). So you can just 
>tie those address lines (A6-A10) low from the DiskOnChip. Connect your 
>CPU's A6 and A7 to the DiskOnChip's A11 and A12, and make your ReadDOC_ and 
>WriteDOC_ macros use (adr & 0x3f | ((adr |0x1800)>>4) as the offset they 
>If you want to boot from it, then use a DiskOnChip Millennium where you can 
>change its firmware to deal with this setup, and wire as many of the extra 
>address lines as you can so you can use as much of the IPL SRAM as possible. 
>If you're only missing one address line, you should be able to see the 
>whole of the IPL SRAM without problems too - wire up A0-A9 normally, and 
>A10,A11 to the DiskOnChip's A11,12. 
This is fantastic news.  I assumed that if the DOC had those address 
lines then it would need all of them.

Is this information true for the 16MB TSOP-I DOC2000 and also the 32MB 
TSOP-I DOC Millenium Plus ???  Aparently they are pin compatible and can 
be used as a drop in replacement for each other.

Brendan Simon.

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