OK, I'm a novice with the 8051. How do you map a port pin to an external interrupt (or visa versa, say External interrupt 2)? I'm assuming that there are no dedicated pins for each of the seven Ex. interrupts on my chip and they have to be assigned somehow to a pin/bit on a specific port. Is this assumption correct? -Michael
Hi Mark, Thanks for the info. The 8051 I'm using is actually embedded in a Cypress USB chip (CY7C646xx, aka EZ-USB FX). It has 7 external interrupts (one dedicated to USB another dedicated to I2C) and three timers. The part is cheap in quantities, I don't know about singles. The info I was looking for WAS hidden in the tech reference but I had to bounce all over the book to find it.