On Thursday 03 May 2001 05:49, Adolf Ahmad MS wrote:
> Dear All,
>
> I need a help.....
>
> I have a problem during capture data stream with data rate(sampling) 782
> kByte/s using PPI8255 Card(ISA Bus). To capture the data stream, i applied
> IRQ triggering.
>
> But, some times many byte of data are lost. How many maximum transfer rate
> on RTLINUX ?
No maxmum transfer rate, really, but there are hardware limitations on the
IRQ response times...
> As info, there is no problem if applied this program to capture the data
> stream with 100 kByte/S.
100 kHz isn't bad for anything with a "normal" CPU in it! You're spending
most of the CPU cycles on context switching here, probably with an occasional
latency peak when the cache is exhausted... (That would be the several lost
bytes when you try to go beyond 100 kHz.)
I *really* think you should consider using DMA, or at least some hardware
buffering... General purpose CPUs really aren't suitable for this kind of
interrupt frequencies.
Isn't there some hardware FIFO or ISA DMA support on that card? (I don't know
anything about the PPI8255...)
//David
.- M A I A -------------------------------------------------.
| Multimedia Application Integration Architecture |
| A Free/Open Source Plugin API for Professional Multimedia |
`----------------------> http://www.linuxaudiodev.com/maia -'
.- David Olofson -------------------------------------------.
| Audio Hacker - Open Source Advocate - Singer - Songwriter |
`--------------------------------------> [EMAIL PROTECTED] -'
-- [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/
