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State Keyword (in State_diagram)

Syntax

[STATE state_exp : [equation]
[equation]
:
:
trans_stmt ; ...]

state_exp - An expression, value, or symbolic state name giving the current state.

equation - A valid equation that defines the state machine outputs.

trans_stmt - IF-THEN-ELSE, CASE, or GOTO statements, optionally followed by WITH transition equations.

Purpose

The state keyword and the associated section describes one state of a state diagram. It includes a state value (or symbolic state name), a state transition statement, and optional state output equations.

Use

The specification of a state description requires the use of the State_diagram syntax (which defines the state machine) and the If-Then-Else, Case, Goto, and With-endwith statements (which determine the operation of the state machine). Symbolic state machines (machines for which the actual state registers and state values are unspecified) require additional declarations for the symbolic state register and state names.

An ending semicolon is required after each transition statement.


See Also

Async_reset and Sync_reset

Using Symbolic State Descriptions

Case

Goto

If-then-else

Module

State (Declaration)

State_diagram

Truth_table

With