Statement Mnemonics

Assembly language instructions must adhere to a fixed set of rules as described here.
An instruction has four separate and distinct parts or FIELDS.

Field

Name

Description

1

LABEL

It is the instruction location’s label or name, and it is used to
reference the instruction.

2

CODE

It defines the operation that is to be performed by the instruction.

3

OPERAND

It provides any address or data information needed by the
CODE field.

4

COMMENT

It is present for the programmer’s convenience and is ignored by the
assembler. The programmer uses comment fields to describe the
operation and thus make the program more readable.

The assembler uses free fields; that is, any number of blanks may separate fields.

Some examples are shown below:

CMI     CLB             / Clear accumulator and carry

LAB,    INC     3       / Increment register 3

        JUN     CMI     / Jump to instruction labelled "CMI"

FCH,    FIM     0P 255  / Load 0xFF (decimal 255) into register pair 0