[LinuxBIOS] Fun easy question. 512Kb or 256Kb

[Bari Ari]

Adam Talbot wrote:

> Speed in ns:
> What controls that? Can I set/change the access speed to my "bios chip"?

The timing of the Flash BIOS read and write cycles are hardwired into 
the chipset and clock synthesizer. At most there is a pinstrap (Pinstrap 
= A signal line on a chipset that is read only after RESET that is used 
to configure the chipset. The line is either tied to a High or Low via a 
resistor.) to chose the type of firmware interface, x8, x16, LPC or FWH.

For an example, see page #3 of this schematic: 
http://www.amd.com/epd/desiging/evalboards/8.am186ccev/22002_1/22002_1.pdf


> I have a few boards that had Eon chips(120ns), I have replaced them with 
> SST's(45ns), they work fine.  Are they running faster? 

No. The chipset spec may just require a flash device of 120ns or less. 
Dropping in a faster flash device doesn't change the read access speed, 
since the speed is driven by the chipset.

-Bari