On Thu, 8 Jul 1999 09:54:42 +0100 (BST),
Doug Rabson <[EMAIL PROTECTED]> said:
dfr> If I understand this correctly, you are suggesting that we program timer0
dfr> so that we only take interrupts when a finetimer is due to fire? If so,
dfr> then it sounds very good. The idea of taking 6000+ interrupts/sec made me
dfr> uneasy, even though most would return without doing any work.
I have been reading the i8254 data sheet for another couple of days,
to find a new problem.
If we have a callout to be made before the timer fires, the counter
needs to be reprogrammed with a new value. We cannot reload the new
counter value immediately; an i8254 does not load the new value until
the currrent period finishes (ie the timer fires) or the gate rises.
Thus a callout will have an average delay of 0.5/hz = 50ms. This is
too long for a timeout in microseconds.
Seigo Tanimura <[EMAIL PROTECTED]>
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