create a variable output pulse stream using interrupts. You are to use OC3 for the interrupt and PortC pin 0 for the output. You should be able to access an eight bit pattern loaded into memory location $0020. Looking at this pattern from left (MSB) to right (LSB), when you see a ‘1' the pulse should be 'ON' for 0.5 seconds. If you see a ‘0', the pulse should be ‘ON' for 1.5 seconds. In either case, the ‘OFF' time should be 2.0 seconds after each ‘ON' time. On reaching the LSB you need to loop back, after the ‘OFF' time for that bit, to the beginning (MSB) and repeat the above process for the same data.
The input to $0020 should be entered using ‘memory modify' through the Buffalo Monitor. The output pin corresponding to PORTC pin 0, should be connected to an LED through a 7406 then the LED then a resistor to Vcc to be able to test the ‘ON' and ‘OFF' time of your pulse.