Re: apic and 8254 wraparound ...

[Alan Cox]

On Gwe, 2004-12-24 at 20:00, Herbert Poetzl wrote:
> somehow I'm unable to locate it, I can see the 
> 430TX and 430HX but not the 430NX and 430LX ...
> 
> do you have an url for me?

Not to hand, its under the retired chipset stuff. The details are as
follows from memory

When you read one 8bit value from an 8254 timer the values latch for
read so that when you read the other half of the 16bit value you get the
value from the moment of the first read. On 
neptune that didn't work right so you got halves of two differing
samples. That means the error would be worst case a bit under 300 (257
for the wrap + a few for timing)

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