Write a few instructions to program the pulse accumulator as

Write a few instructions to program the pulse accumulator as follows: Enable the pulse accumulator; select the gated accumulation mode and a low signal on PAI line should inhibit counting. Wait for 12 overflows. After that when the pulse accumulator content becomes equal to 160, increment the word at location $0120 by 4.

Solution

To use the pulse accumulator connect an input to Port T7 The pulse accumulator operates in two modes: 1. Event-Count Mode 2. Gated Time Accumulation Mode In Event-Count Mode, the pulse accumulator counts the number of rising or falling edges on Port T7 – You can set up the pulse accumulator to select which edge to count – The counts are held in the 16-bit PACNT register – On each selected edge the PAIF flag of the PAFLG register is set – When PACNT overflows from 0xFFFF to 0x0000, the PAOVF flag of the PAFLG register is set In Gated Time Accumulation Mode the pulse accumulator counts clock cycles while in the input to Port T7 is high o