shiftcnt.abl

自己编写的GAL可编程逻辑电路的编译软件abel4的windows界面

module shiftcnt 
title 'universal counter / shift register
Bjorn Benson   Data I/O Corp   31 July 1990'

        IFL4    device 'F159';

        Clk,JKD,I1,I2,I3,OE     pin 1,2,3,4,5,11;
        F0,F1,F2,F3             pin 12,13,14,15;
        F3,F2,F1,F0             istype 'reg_JK,invert';

        H,L,X,Z,Ck      = 1,0,.X.,.Z.,.C.;

" Define counter/shift modes
        mode    = [I3,I2,I1,JKD];               " [I3,I2,I1,JKD]
        Down    = [ 0, 1, 0, 1 ];       Left    = [ 0, 1, 0, 0 ];
        Up      = [ 0, 0, 1, 1 ];       Right   = [ 0, 0, 1, 0 ]; 
        Clear   = [ 1, X, X, X ];

" Group register outputs into set
        count           = [F3,F2,F1,F0];

equations
" Count Down    JK (T) Flip/Flop
        [F0.J,F0.K] = (mode == Down) ;
        [F1.J,F1.K] = (mode == Down) &                 !F0.Q;
        [F2.J,F2.K] = (mode == Down) &         !F1.Q & !F0.Q;
        [F3.J,F3.K] = (mode == Down) & !F2.Q & !F1.Q & !F0.Q;

" Count Up      JK (T) Flip/Flop
        [F0.J,F0.K] = (mode == Up)   ;
        [F1.J,F1.K] = (mode == Up)   &                 F0.Q;
        [F2.J,F2.K] = (mode == Up)   &          F1.Q &  F0.Q;
        [F3.J,F3.K] = (mode == Up)   &  F2.Q &  F1.Q &  F0.Q;

" Shift Left    D Flip/Flop
        F0.J = (mode == Left)  & F3.Q;
        F1.J = (mode == Left)  & F0.Q; 
        F2.J = (mode == Left)  & F1.Q;
        F3.J = (mode == Left)  & F2.Q;

" Shift Right   D Flip/Flop
        F0.J = (mode == Right) & F1.Q;
        F1.J = (mode == Right) & F2.Q;
        F2.J = (mode == Right) & F3.Q;
        F3.J = (mode == Right) & F0.Q;
@page 
equations
        [F3,F2,F1,F0].OE = !OE;
        [F3,F2,F1,F0].FC = JKD;        
        [F3,F2,F1,F0].C  = Clk;        
        [F3,F2,F1,F0].RE = (mode == Clear);    

test_vectors  'Count Up and Shift Left'
       ([Clk,OE,mode ]  ->  count) 
        [ Ck, L,Clear]  ->    !0  ;
        [ Ck, L,Up   ]  ->    !1  ;
        [ Ck, L,Up   ]  ->    !2  ;
        [ Ck, L,Up   ]  ->    !3  ;
        [ Ck, L,Left ]  ->    !6  ;
        [ Ck, L,Left ]  ->    !12 ;
        [ Ck, H,Left ]  ->    Z   ;

test_vectors  'Shift right'
       ([Clk,OE,mode ]  ->  count )
        [ Ck, L,Clear]  ->  ^b1111;
        [ Ck, L,Down ]  ->  ^b0000;
        [ Ck, L,Down ]  ->  ^b0001;
        [ Ck, L,Right]  ->  ^b1000;
        [ Ck, L,Right]  ->  ^b0100;
        [ Ck, L,Right]  ->  ^b0010;
        [ Ck, L,Right]  ->  ^b0001;

test_vectors   'Shift left'
       ([Clk,OE,mode ]  ->  count )
        [ Ck, L,Clear]  ->  ^b1111;
        [ Ck, L,Up   ]  ->  ^b1110;
        [ Ck, L,Left ]  ->  ^b1101;
        [ Ck, L,Left ]  ->  ^b1011;
        [ Ck, L,Left ]  ->  ^b0111;
        [ Ck, L,Left ]  ->  ^b1110;

test_vectors   'Count up'                               
       ([Clk,OE,mode ]  ->  count )
        [ Ck, L,Clear]  ->    !0 ;
        [ Ck, L,Up   ]  ->    !1 ;
        [ Ck, L,Up   ]  ->    !2 ;
        [ Ck, L,Up   ]  ->    !3 ;
        [ Ck, L,Up   ]  ->    !4 ;
        [ Ck, L,Up   ]  ->    !5 ;
        [ Ck, L,Up   ]  ->    !6 ;
        [ Ck, L,Up   ]  ->    !7 ;
        [ Ck, L,Up   ]  ->    !8 ;
        [ Ck, L,Up   ]  ->    !9 ;
        [ Ck, L,Up   ]  ->   !10 ;
        [ Ck, L,Up   ]  ->   !11 ;
        [ Ck, L,Up   ]  ->   !12 ;
        [ Ck, L,Up   ]  ->   !13 ;
        [ Ck, L,Up   ]  ->   !14 ;
        [ Ck, L,Up   ]  ->   !15 ;
        [ Ck, L,Up   ]  ->    !0 ;
end