Briefly Discuss about Microprocessor Input/Output

There are three ways of transferring data between the microcomputer and physical I/O devices;

1. Programming I/O
2. Interrupt driven I/O
3. Direct memory Access

The microcomputer executes a program to communicate with an external device via a register called the I/O port for programmed I/O. an external device requests the microcomputer to transfer data by activating a signal on the microcomputer interrupt line during interrupt I/O . in response the microcomputer executes a program called the interrupt service routine to carry out the function desired by the external device again by way of one or more I/O ports. Data transfer between the microcomputer memory and an external device occurs without microprocessor involvement with direct memory access. Read More