what is IRQ trigger ????

fritoss007 · Post by **fritoss007** » Tue May 30, 2006 5:35 am

what is irq trigger ????

boost junkie · Post by **boost junkie** » Tue May 30, 2006 5:55 am

It's a digital pulse on the IRQ pin of the cpu that interrupts the normal flow of software to do something else. The megasquirt uses the irq pin for rpm input or to read a toothed crank wheel. Each time the digital signal goes from high to low an IRQ is triggered and the sofware jumps to a section of code that counts teeth and schedules the ignition events...