A ProASIC constraint consists of a statement and an argument, terminated by a semicolon. Statements are not case sensitive. However, cell instance, net, and port names used as arguments may be quoted and are case sensitive. Except for white spaces, all ASCII characters can be used. Comments are allowed in constraints files and must be preceded by two forward slashes (//). Time values are given in nanoseconds. When constraints are duplicated, the last one specified for a specific item overwrites any previous similar constraints already specified for the considered item.
This section describes syntax conventions for notation, user data variables, and comments. Comments begin with double slashes (//) and are terminated by a newline character.
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Syntax Conventions for Notation |
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Notation |
Description |
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item |
Represents a syntax item |
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item ::= definition |
item is defined as definition |
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item ::= definition1
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item is defined as either definition1 or definition2
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[ item ] |
Item is optional |
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{ item } |
Item is a list of required items. At least one item must appear. |
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KEYWORD |
Keywords appear in uppercase characters in bold type for easy identification, but are not case sensitive. |
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VARIABLE |
Represents a variable and appears in uppercase characters for easy identification |
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Syntax Conventions for User Data Variables |
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Variable |
Description |
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FILEIDENTIFIER |
Represents a hierarchical filename. |
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IDENTIFIER |
Represents the name of a design object. Can be a block, cell instance, net, or port. IDENTIFIERS can use any ASCII character except the white space and the slash (/), which is the hierarchical divider character (see QPATH below). IDENTIFIERS are case sensitive |
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POSFLOAT |
Represents a positive real number; for example, 4.3, 1.15, 2.35 |
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POSNUMBER |
Represents a positive integer; for example, 1, 12, 140, 64. When representing time, POSNUMBER is expressed in nanoseconds (ns) |
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QPATH |
Represents a hierarchical IDENTIFIER. The levels of the hierarchy are represented by IDENTIFIERS divided by a slash (/). The QPATH hierarchical IDENTIFIER may or may not be quoted |