one interrupt, and the number on the monitor increases by one, after 5 times of interrupt, the program ends. 1 3 Referred Flowchart START 2 Experiment 2 Interrupt Objective 1.1 Know the principle of interrupt of microprocessor 1.2 Learn how to write the interrupt service routine Principle and contents 2.1 Only mask-able interrupt could be used by users as hardware interrupt, and is managed by 8259 interrupt controller. Interrupt controller is used for receiving interrupt request from outside, and sent to the interrupt request to the CPU after judging the priorities. The system has set the interrupt request as 'edge sensitive'. Set the interrupt vector (IR27) Interrupt Enable (IRQ7) 2.2 Contents Set the counter of interrupt LOOP Flowchart of program in CPU 4 Tips In this experiment, we are going to use 8255 for data transmission, take Figure 1 as example, we pass the data from port B in the 8255 chip to monitor, so it's better to familiarize yourself with how the 8255 works first. IBA | Figure 1 The circuit of experiment is shown as Figure 1. Chips needed for this experiment are 8086, 8255, 8259, 74LS08, 74LS138, 74LS245, 74LS373, BUTTON, CHIPRES18R, SEG-COM-CATHODE. Finish the layout and connection of the circuit. And then program with assemble language to achieve following function. One push on the button should generate