Re: PCI WRITE TO XROM region

["Monish Shah" <monish@hpfcmss.fc.hp.com>]

On Oct 22,  2:15pm, Mohamad Tisani wrote:

...

> if there is a write cycle to the region pointed to by the Expansion Rom
> Base Address ( PCI CONFIG OFFSET = 30) region what is the best thing to do
> :
>
>
> 1- do not assert devsel , as if the cycle is not yours
> 2- assert devel & do a target abort
> 3- write the data & change your eprom -- not pretty

There's another option:

4- Complete the write on PCI but don't write the data to the EPROM.

This is usually what happens when software writes a memory mapped ROM.

> the ROM needed for this PCI controller have a certain method to change the
> ROM  through a back door way .( write address , write data , issue a
> command ) .
>
> Thanks
>
> ***********************************
> Mo Tisani , Senior Systems Engineer
> ***********************************

Monish Shah
Hewlett Packard
¨È¶