3. Instruction set

Assembly language consists of a set of mnemonics that can be used to program a CPU. There are a number of mnemonics that together make up the complete instruction set of the CPU. They can be grouped according to the kind of processing they cover.

For example, in the Intel 80186 instruction set some of the mnemonics are

Arithmetic mnemonics : ADD, SUB, DIV, MUL

Data transfer mnemonics: MOV, POP, IN, OUT

Logic mnemonics : AND, OR, XOR, NOT

Jump mnemonics : JMP, JZ (jump if zero)

Miscellaneous mnemonics : NOP (Do nothing for a bit)

One of the skills in writing assembly code is to become familiar with the instruction set of the target CPU.