module Z74X138P 
title '74x138 Decoder PLD with extra enables and polarity control
J. Wakerly, Stanford University' 
"Z74X138P device 'P16V8'; 

" Input pins 
A, B, C, !G2A, !G2B, G1      pin 1, 2, 3, 4, 5, 6;
EN1, !EN2                    pin 7, 8; 
POL                          pin 9;

" Output pins
!Y0, !Y1, !Y2, !Y3           pin 19, 18, 17, 16 istype 'com'; 
!Y4, !Y5, !Y6, !Y7           pin 15, 14, 13, 12 istype 'com';

" Constant expression
ENB = G1 & G2A & G2B # EN1 # EN2;

equations
Y0 = POL $ (ENB & !C & !B & !A); 
Y1 = POL $ (ENB & !C & !B &  A); 
Y2 = POL $ (ENB & !C &  B & !A); 
Y3 = POL $ (ENB & !C &  B &  A); 
Y4 = POL $ (ENB &  C & !B & !A); 
Y5 = POL $ (ENB &  C & !B &  A); 
Y6 = POL $ (ENB &  C &  B & !A); 
Y7 = POL $ (ENB &  C &  B &  A);

end Z74X138P