Instruction Types

The instruction set of a CPU can be categorized as follows:

Data Processing:

Arithmatic and Logic instructions Arithmatic instructions provide computational capabilities for processing numeric data. Logic (Boolean) instructions operate on the bits of a word as bits rather than as numbers. Logic instructions thus provide capabilities for processing any other type of data. There operations are performed primarily on data in CPU registers.

Data Storage:

Memory instructions are used for moving data between memory and CPU registers.

Data Movement:

I/O instructions are needed to transfer program and data into memory from storage device or input device and the results of computation back to the user.

Control:

Test and branch instructions
Test instructions are used to test the value of a data word or the status of a computation. Branch instructions are then used to branch to a different set of instructions depending on the decision made.