Chapter 9 Writing Machine Language Instructions and Directive Statements

9.2.1Writing Label Field

Labels are called both symbols and names. The assembler assigns a label the value of the location counter at the point it is defined.

Coding rules

Labels can use upper-case and lower-case letters, digits, underscores (_).

Labels are coded in the first column.

The first character of a label must not be a digit.

Labels are case sensitive.

The same label name cannot be defined twice.

When the label is omitted, it must be replaced with at least one space or tab.

Terminology: * Column

This is a column on the display or printer paper. One character takes one column. Columns are counted from the left as column 1, 2, etc.

Coding examples

LABEL LONGLABELLONGLABELLONGLABELLONGLAB main

start_cont

The following examples are incorrect.

1LABEL

; Starts with a digit

@START

; Uses a prohibited character

START

; Does not start from the first column

148 Instruction Statement Fields

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Panasonic MN1030 user manual Writing Label Field, Coding examples, Label Longlabellonglabellonglabellonglab main Startcont