On Sat, 25 Sep 1999, Reef Morse wrote:
> what is the minimum interrupt period that can be handled. I'd like to be around
> 25 microseconds, AND have time left over for handling all the other tasks.
> The system will be acquiring data from an A/D in real time, and communicating
> that data over the net to another computer. Will the communication timing foul
> up the A/D, and will the A/D found up communication?
Will be tough, but if you do not have too much data to transmit, could work.
Keep in mind that every ISA read/write of byte or word takes at least
1.25 us. So 25 us is much too litle time to send a packet over ISA network
card. Assuming with every IRQ you will just read 2 bytes from A/D and that
network does not need to be hard real time (one packet per several A/D
interrupts) it could work. Definitely, the priority of A/D ISR needs to be
higher than network. So your routine sending packet will be interrupted a few
times by A/D interrupt - but this should be no problem.
Expect 2-5 us delay on RT interrupts. If you manage to do your part of ISR
in 5-10 us it should work leaving 5-10 us for the Linux kernel and user
processes.
--
Tomek Motylewski
--- [rtl] ---
To unsubscribe:
echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR
echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED]
----
For more information on Real-Time Linux see:
http://www.rtlinux.org/~rtlinux/
