- From: Nils Juergens <ju_at_isf.rwth-aachen.de>
- Date: Tue, 06 Apr 2004 16:36:12 +0200
On Tue, 06.04.04, Steve Sharples <sds_at_eee.nott.ac.uk> wrote: > (2) use one of the 8255 port C lines to gate one of the 8254 > counter/timers to produce a pulse of the correct length (using "Mode 1, > Hardware re-triggerable one-shot"), which is then applied to the GATE > input of the counter/timer that's providing the convert clock pulses. This may work, but are you sure you can generate a long enough pulse with just one 16 bit counter? Another idea would be to use a (mode 1)counter to count the converter clock pulses (attaching 'out' of the rate generator to 'clock' of the counter) and gate the rate generator with the (inverted) output of the (mode 1)counter. But i see no way of restarting the counter after it has reached terminal count (because the counter won't do anything without the clock from the rate generator, which is not running because the counter is blocking it). > I can't help feeling that there has to be an easier way! I'm sure I just > need someone to say "have a look at the xxxx driver, it's all explained > perfectly"! I tried to do something similar with another board (advantech pci 1710) but came to the conclusion it was not possible (without additional hardware). But then again i can't influence the GATE of the rate generator on my board like it is possible on your board, so this may not be true for you. good luck, Nils
Received on 2004-04-06Z13:36:12