On 4/17/07, James Richard Tyrer <[EMAIL PROTECTED]> wrote:
Have I been the victim of Intel hype? They make hardware that would make it possible to have enough interrupts for each PCI card slot to have 4 interrupts or at least to have 24 hardware interrupts available to be assigned with a cross point.
On a PCI bus, there are four interrupt lines. All four are connected to each slot, but in a different order. In some Sun hardware, each slot has its own set of interrupt lines. But they do other weird stuff too. Also, in general, there are many sources of interrupts in a PC, but they all route to one priority encoder that hands a binary number to the CPU that tells it which one to pay attention to. Then it comes down to the ISR looking to figure out which source it is and so forth. You're never going to get away from the fact that you have to query devices to figure out which one asserted the interrupt, because you cannot tell just from the interrupt number. -- Timothy Normand Miller http://www.cse.ohio-state.edu/~millerti Open Graphics Project _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
