module IFTEST 
title 'Alternate Version of Example State Machine' 

" Input and output pins 
CLOCK, RESET_L, A, B            pin;
LASTA, Q1, Q2                   pin istype 'reg';
Z                               pin istype 'com';

" Definitions 
QSTATE  = [Q1,Q2];               " State variables 
INIT    = [ 0, 0];               " State encodings 
LOOKING = [ 0, 1]; 
OK      = [ 1, 0]; 
XTRA    = [ 1, 1];
RESET = !RESET_L;

state_diagram QSTATE

state INIT:    IF !RESET THEN LOOKING ELSE INIT;

state LOOKING: IF !RESET THEN
                 {IF (A == LASTA) THEN OK
                  ELSE LOOKING;}
               ELSE INIT;

state OK:      IF !RESET THEN 
                 {IF B THEN OK
                 ELSE IF (A == LASTA) THEN OK
                 ELSE LOOKING;}
               ELSE INIT;

state XTRA:    GOTO INIT;

equations
LASTA.CLK = CLOCK; QSTATE.CLK = CLOCK; " QSTATE.OE = 1;

LASTA := A;
Z = (QSTATE == OK);

END IFTEST