lib/sema.txt
author laurent
Tue, 11 Oct 2011 12:30:49 +0200
changeset 382 ac6dfec701c9
parent 251 5e7457efbb8f
permissions -rw-r--r--
Fix bug in parser while trying to use IL operator like S1, R1, etc... as standard function block interface variable in structured_variable syntax and bug in code generator while generating code for assignment of function block interface variable using structured_variable syntax
(*
 * (c) 2011 Edouard Tisserant
 *
 * Fake semaphore support, for non preemptive implementation.
 *
 *)


FUNCTION_BLOCK SEMA
  VAR_INPUT
    CLAIM : BOOL;
    RELEASE : BOOL;
  END_VAR
  VAR_OUTPUT
    BUSY : BOOL;
  END_VAR
  VAR
    Q_INTERNAL : BOOL;
  END_VAR

  Q_INTERNAL := CLAIM OR ( Q_INTERNAL AND (NOT RELEASE));
  BUSY := Q_INTERNAL;

END_FUNCTION_BLOCK