| Operation | Behavior | Note |
|---|---|---|
| Addition (ADD) | A + B | Arithmetic addition. Address generation. |
| Subtract (SUB) | A - B | Arithmetic subtraction |
Logial operations
| Operation | Behavior | Note |
|---|---|---|
| Logical and (AND) | A and B | Bitwise logical AND |
| Logical or (OR) | A or B | Bitwise Logical OR |
| Logical not (NOT) | not A | Bitwise not, 1's complement |
Shift and exchange operations
| Operation | Behavior | Note |
|---|---|---|
| Arithmetic shift right (ASR) | |
Arithmetic right shift, Divid operand A by 2 |
| Arithmetic shift left (ASL) | |
Arithmetic left shift, Multiply operand A by 2 |
| Nibble swap (SWP) | Exchange upper nibble and lower nibble of operand A | for nibble operation |
The followings are steps for design and implementation of the ALU.