Miguel Saiz Arnedo wrote: > > Hello. > > I installed RTLinux on my AMDk6 430 MHZ with 128 Mb RAM and up to now I've just > been probing with the example programs. > I have tried the hello.c with various thread periods and observed that when I > try periods of less than 10us my system crashes. Is this a normal limit? Is it > a > hardware limit or is it an RTLinux limit?
The way you put it is not the right one. Doing what you want is easy. Just my figures. With a PII 233 MHZ, 32 MB I can prove it possible to run a 100 KHz task doing 4 inb/outb, likely enough to control a mux and start_get_conv in software, while still using a very very sluggish Linux, so there is margin for catching up with some jitter also. Clearly to do it all in 10 us the soft way you need a converter of about 200 KHz AD sampling rate. The real point is that you will be sampling at 100KHz on the average but get latencies of 10us, and even worse, now and then. In any case if you can live with some jitter you'd better forget a task, have an end of conv interrupt and dowload the sample directly in an interrupt handler. Buying a more expansive card is a choice but is not that much fun as getting what you want at a lower cost. Paolo. -- [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/
