Multiprocessor system

[Brad Sheridan]

> 
> 
> >Pardon my ignorance here, but what the heck do you need more than 1 output
> >compare for?  You only have 1 cylinder firing at a time 
> 
> Wrong. At WOT (I'm fed up with yanks pussy footing it around. Get your foot
> down :), All of the injectors can be open at the same time.
 
 Would it be possible to make some sort of FIFO structure that kept track of
the time to go into the output compare, and a mask to tell you which
injector to be turned off? Given that you know how many cylinders you have(I
hope :), the FIFO can be of a fixed size:2 bytes for OC value, 1 for mask per
cylinder, with an extra pair of bytes to tell you where the beginning and
end of the valid info is. Every time the OC was triggered, it could load the
next value from the queue into the OC. You'd need an available output port
to do this, but I think it could be done. One potential problem would be if
two injectors were to be closed in a time frame shorter than the length of
time for the interupt to be serviced. This shouldnt be too much a problem if
the OC is kept as a high priority, and the interrupts aren't too long. How
does the aftermarket deal with this? Or do they use chips with more output
compares?

Brad Sheridan