/* GAL for dummy exchange   A.J. Fisher	  September 1995 */

DEVICE gal (gal16v8)

#define ACTIVE_LOW     XOR_0
#define ACTIVE_HIGH    XOR_1
#define COMBINATORIAL  SYN_0 AC0_1 AC1_1
#define REGISTERED     SYN_0 AC0_1 AC1_0

PIN
   clk	  = 1  (CLOCK)
   /aoff  = 2  (INPUT)
   /boff  = 3  (INPUT)
   pin4	  = 4  (INPUT)
   pin5	  = 5  (INPUT)
   pin6	  = 6  (INPUT)
   pin7	  = 7  (INPUT)
   pin8	  = 8  (INPUT)
   pin9	  = 9  (INPUT)
   gnd	  = 10 (GND)

   vcc	  = 20 (VCC)
   aring  = 19 (OUTPUT COMBINATORIAL ACTIVE_HIGH)
   bring  = 18 (OUTPUT COMBINATORIAL ACTIVE_HIGH)
   la	  = 17 (OUTPUT COMBINATORIAL ACTIVE_LOW)
   lb	  = 16 (OUTPUT COMBINATORIAL ACTIVE_LOW)
   q2	  = 15 (OUTPUT REGISTERED ACTIVE_HIGH)
   q1	  = 14 (OUTPUT REGISTERED ACTIVE_HIGH)
   q0	  = 13 (OUTPUT REGISTERED ACTIVE_HIGH)
   pin12  = 12 (OUTPUT REGISTERED ACTIVE_HIGH)
   /oe	  = 11 (CONTROL)

   pte1	  = 21 (OUTPUT)
   pte2	  = 22 (OUTPUT);

BEGIN

   ENABLE(pte1, pte2);			/* set PT enable bits */
   ENABLE(la, lb, aring, bring);	/* enable combinatorial o/ps */

   /* cross-coupled latch */
   la	  = (aoff * boff * /q2 * q1 * q0) + lb; /* really defines /la */
   lb	  = (/aoff * /boff) + la;		/* really defines /lb */

   q2	  = (q2 % q1*q0) + (/aoff * /boff);
   q1	  = (q1 % q0)	 + (/aoff * /boff);
   q0	  = (q0 % 1)	 + (/aoff * /boff);

   aring  = /lb * /q2 * /q0 * boff * /aoff;	/* (/q2 * /q0) is cadence */
   bring  = /lb * /q2 * /q0 * aoff * /boff;

END.