Interrupts in 8051 8051 Micro-controller by Ravinder Nath Rajotiya - December 3, 2021December 3, 20210 Interrupts in 8051 What is an Interrupt: It is a requesting mechanism for the peripherals to make the microcontroller interrupt the currently executing program and run the program to service the request. The program that is run upon the interrupt is called an ISR (interrupt service routine) Types of Interrupts in 8051 There are five different sources of interrupts A real life example - Before going to sleep, you set the timer. Then forget what the timer does, and go for sleep. When the timer finishes the counting, it alarms and interrupts you from sleep. You then wake and starts doing your routine. sources of interrupt in 8051 are: Timer-0: Timer-0 interrupts Timer-1: Timer-1 interrupts Serial Rx/Tx INT0 INT1 All interrupts in 8051 are vectored interrupts Interrupt
Experiment-5 Reading a number from One Port and Sending it to another Port 8086 Programming by Ravinder Nath Rajotiya - April 15, 2021May 9, 20220 Aim: Write a Program to read 16 bit Data from a port and display the same in another port. Objectives: [ To learn configuring of Key board and display module with 8086 microprocessor using 8255PPI Design algorithm and develop a program for accepting data from oneport and displaying it to LCD connected to other port. Equipment Require: 8255 Display Module, 8086 trainer Kit Theory: A Simple approach We can make use of the 8086 IN and OUT instruction to read the data from the device attached to a port and send the data to another port. We can access the ports using direct addressing or indirect addressing Direct address can be provided in the instruction Indirect address is loaded in DX register. here is simple program statements for the
Interrupts in 8085 and interrupt cycle 8085 Microprocessor by Ravinder Nath Rajotiya - August 28, 2020February 28, 20220 We can define interrupt as a process or techniques using which an external slow speed device seek the attention of the microprocessor to informs that it is ready for communication with it. In this post we learn about the interrupt, interrupt cycle and the types of interrupts for 8085 microprocessor
8259 Priority Interrupt Controller Microprocessor and Interfacing by Ravinder Nath Rajotiya - March 27, 2020May 6, 20220 8259 Programmable Interrupt Controller The Intel 8259A programmable Interrupt Controller (PIC) is one of the most common interrupt controller used in IBM PCs. It can handle eight vectored priority interrupts for the CPU. It is a 28 pin DIP package and requires a single +5V DC supply for its operation. It is designed to minimize the software and real time overhead in handling multi-level priority interrupts. It has several modes, permitting optimization for a variety of system requirements. The pin diagram of 8259A is shown in figure-1 below. PIN Number Pin Name Description 1 CS’ Chip Select Input 2 WR’ Write control signal 3 RD’ Read control signal 4-11 D7-D0 Data Bus 12-13, 15 CAS0, CAS1 Cascade control 14 GND Ground 16 SP’/EN’ 17 INT Interrupt output for processor 18-25 IRQ0 – IRQ7 Interrupt request inputs 26 INTA Interrupt Acknowledge input 27 A0 Address input 28 VCC +5V supply 8259 interrupt Overview If the 8086 interrupt flag is set and INTR