To link the controller with the other parts of the system and to
get inputs from the outside world

an example of Input devices and circuits

For transferring data serially between the controller & other systems.

For transferring data in parallel between the controller & other systems.

Interrupt controller is used to enable the CPU of the controller to interrupt its running
operations and run other operations required by fired events.

The circuits that execute instructions for a program control task,
such as interrupt or jump to another set of instructions

It has circuits that implement the instructions pertaining to data
transfer operation and data conversion from one form to another

It includes a fetch unit for fetching instructions from the memory

minimize the number of
instructions per program, sacrificing the number of cycles per
instruction

RISC is reducing the cycles per instruction at
the cost of increasing the number of instructions per program.

Difficult to program

simpler design of compiler

Many addressing modes causing complex instructions formats

Low clock cycle per second

Emphasis is on software

Faster Execution

in RISC each instruction is to be executed by

in CISC instructions are to be read from memory and