Basic Syntax

Each line in an ABEL-HDL source file must conform to the following syntax rules and restrictions:

A line can be up to 150 characters long.

Lines are ended by a line feed (hex 0A), by a vertical tab (hex 0B), or by a form feed (hex 0C). Carriage returns in a line are ignored, so common end-of-line sequences, such as carriage return/line feed, are interpreted as line feeds. In most cases, you can end a line by pressing Enter.

Keywords, identifiers, and numbers must be separated by at least one space. Exceptions to this rule are lists of identifiers separated by commas, expressions where identifiers or numbers are separated by operators, or where parentheses provide the separation.

Neither spaces nor periods can be imbedded in the middle of keywords, numbers, operators, or identifiers. Spaces can appear in strings, comments, blocks, and actual arguments. For example, if the keyword MODULE is entered as MOD ULE, it is interpreted as two identifiers, MOD and ULE. Similarly, if you enter 102 05 (instead of 10205), it is interpreted as two numbers, 102 and 5.

Keywords can be uppercase, lowercase or mixed-case.

Identifiers (user-supplied names and labels) can be uppercase, lowercase or mixed-case, but are case sensitive: the identifier, output, typed in all lowercase letters, is not the same as the identifier, Output. Reserved keywords can not be used as identifiers;

See Also

Supported ASCII Characters