mtd: looking for serial flash storage
Brendan J Simon
brendan.simon at bigpond.com
Tue Oct 9 03:00:36 EDT 2001
David Woodhouse wrote:
>hamishl at dplanet.ch 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.
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