Page 1 of 1
PIT counters
Posted: Fri Dec 31, 2004 4:28 pm
by ManOfSteel
Hello,
Is there any difference between the three PIT counters? If yes, then which one do I have to use in which situation?
Thank you in advance.
Re:PIT counters
Posted: Sat Jan 01, 2005 1:46 am
by Brendan
Hi,
ManOfSteel wrote:
Hello,
Is there any difference between the three PIT counters? If yes, then which one do I have to use in which situation?
There's no difference in how each channel works, but the output of each channel is connected to different things. In general:
Channel 0: Used for system timer tick. Output connected to IRQ1.
Channel 1: Used for DMA refresh on old machines (output connected to RAM controller). Not connected to any IRQ.
Channel 2: Used for "PC speaker" control - output connected to speaker, so setting channel 2 frequency determines speaker tone. Not connected to any IRQ.
Cheers,
Brendan