What are the basic requirements for proper interface between a microprocessor and an l/O device? Discuss with diagrams.

Subject Peripheral and Interfacing
NU Year Set: 1.(c) Marks: 6 Year: 2017

There are a number of generic types of I/O. An attempt to categorize those we will discuss is shown. Here we are primarily concerned with I/O that directly involves the CPU accessing registers on a device. This is called Programmed I/O, as opposed to Direct Memory Access and Channel I/O that will be mentioned in passing later. Within programmed I/O we will compare and contrast Port-mapped I/O with Memory mapped I/O, and will conclude that they are actually very similar, but that Port mapped is more suited to microcontrollers. Last we will contrast Polled I/O with Interrupt-driven I/O, the latter being a method of allowing devices to initiate I/O and hence avoid the waste of CPU cycles in the former.

Login to post your comment.