Re: [Qemu-devel] SPI EEPROM device model

[Peter Crosthwaite]

On Mon, Nov 30, 2015 at 12:53 AM, Krzeminski, Marcin (Nokia -
PL/Wroclaw) <address@hidden> wrote:
> Hello,
>
> I need to write some SPI eeprom device model (probably AT25128B or AT93C56).
> I can not see any such device in qemu, but this time I want to ask before I 
> start to implement,
> if something that can speed up work is already present somewhere ?
> Maybe do you have some preferences which eeprom device is better to have in 
> qemu?
>

So some of those EEPROM devices are nearly identical to M25P80 in
functionality, the main difference being that individual cells can be
programmed from 0 back to 1. A quick look at a AT25128B datasheet
looks like this may be the case. Read and write instructions as the
same encoding as M25P80.

Search m25p80 for WR_1, which is a flag you can set that allows write
of 1 to individual bits. I think can become a feature of M25P80 (more
table entries) if the basic instructions are just an M25P80 subset.

HTH

Regards,
Peter

> Regards,
> Marcin