DESCRIPTION

This document describes the CTL file format used by moka(1) for model checking of finite states machine description.

This CTL file format subset is defined to enable classical CTL formulae description.
A CTL file is made of two parts: a declaration part and a formulae statement part.

The declaration part described types, constants, macros and all variables used in CTL formulae. It also describes assumption conditions and initial conditions that have to be applied by moka(1) during the model checking.

The formulae statement part described all the CTL formulae that have to be verified.

All boolean and relational VHDL operators are supported (see vbe(5)) and also the 8 CTL operators AF, AG, AX, AU, EF, EG, EX and EU. The CTL file format support also the imply boolean operator '->' and the equivalence operator '<=>'.

EXAMPLE

--  user type definition
   TYPE A_ETAT_TYPE IS (A_E0, A_E1);
   TYPE B_ETAT_TYPE IS (B_E0, B_E1);
--  variables definition
   VARIABLE A_NS, A_CS : A_ETAT_TYPE;
   VARIABLE B_NS, B_CS : B_ETAT_TYPE;
   VARIABLE    ck       : BIT;
   VARIABLE    data_in  : BIT;
   VARIABLE    data_out : BIT;
   VARIABLE    reset    : BIT;
   VARIABLE    ack      : BIT;
   VARIABLE    req      : BIT;
-- example of a macros definition
   DEFINE      def1     : BOOLEAN := ack='1';
-- the assigned value can be a constant
   DEFINE      c1       : BIT  := '1';
-- the assumption condition
   ASSUME   ass1  := (reset='0');
-- the initial reset condition
-- be careful, the assumption condition is not applied 
-- to the initial conditions.
   RESET_COND init1 := (reset='1');
-- It is also possible to describe the first state
-- with the INITIAL keywork, as follows:
--
-- INITIAL init1 := ((A_CS=A_E0) AND (B_CS=B_E0));
--
-- formulae description statement part
begin
   prop1 : EX( ack='1' );
   prop2 : AG( req -> AF( ack ) );
   prop4 : AU( req='1', ack='1');
end;