Many cheap mainboards with integrated CPUs do 100k interrupts per second (100k steps per second in quadrature outputs) pretty well. We need to see the difference betwee the step/dir output and clean, fast quadrature output as step/dir output can reach at most 50% of the output step speed of the quadrature output.
On Mon, Mar 2, 2009 at 5:46 AM, Jon Elson <[email protected]> wrote: > John Kasunich wrote: >> Jon Elson wrote: >> >> >>> Even getting 200 KHz output with complex code is very unlikely. You >>> would need to set the interrupt frequency to 200 KHz = 50 us, >>> >> >> 200KHz interrupts is a 5uS period, not 50uS. Not happening on any PC. >> I think Alex Joni once got the period down to about 6.5uS, just to see >> how far he could go. The machine was not very usable at that point. >> >> > OOPs, off by an order of magnitude! Yes, getting interrupts down much > below 15 us, even on multi-core CPUs, is just about impossible. > > Sorry for the mistake. So, software-generated step pulses up to 50 KHz > or so is possible on some programs, but already pushing things pretty far. > Mach has some tricks to handle pulses between interrupts and can go a > bit higher. Eventually, the high-end CPU needed to do this costs more > than some of the hardware assist devices available. > > Jon > > > ------------------------------------------------------------------------------ > Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA > -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise > -Strategies to boost innovation and cut costs with open source participation > -Receive a $600 discount off the registration fee with the source code: SFAD > http://p.sf.net/sfu/XcvMzF8H > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers > ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
