An open ended Problem.

Design an 8086 based microprocessor system that monitors the temperature of a room using a temperature sensor attached to an 8255 programmable IO port. The sensor is connected to port A in mode 0. The requirement is that the system has to read the sensor data every 15 second and compare with the old data. If the incoming temperature value is less 10 F from the previous value the CPU initiates an alarm. To keep the time the design engineer (YOU) is using 74163 as time keeper. The system must be interrupt driven.

It is your responsibility to Decide:

Size of the ROM, SRAM and their location in the memory space.

8255, 74163 decoding circuit

Interrupt vector address

ISR location in the SRAM

ISR vector address

Necessary INTR Hardware

ISR software