In the case of CPU initiated I/O transfer, it is the Microprocessor which through a software initiates the action of data transfer.
some of the output devices interfaced are LED s, seven segment displays, TTY, CPT, printers, digital to analog converters etc.
In addition to the memory and keyboard interfaced to the Microprocessor many input & output peripheral devices may have to be interfaced with the system to obtain a micro-computer depending upon a particular control applications same of the input devices interfaced are push bottom switches, toggle switches, a TTY, CRT, analog to digital converters etc. This transfer of data is in addition to transfers between the microprocessor and memory and is referred to as input/output or I/O. In all process content applications, Microprocessor would like to communicate with different I/O devices for data transfers is transfer of data between circuitry external to the Microprocessor itself.
