regfb.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 regfb
title 'Operation of the simulator on devices with feedback
       Data I/O Corp.      31 July 1990'

        FB2     device 'P16R4';

        Clk,OE          pin 1,11;
        INIT,D1,D2,D3   pin 2,3,4,5,;
        F1,F2           pin 14,13;

        F1 istype 'reg_D,invert';

equations
        F1.D    = D1 & INIT;
        F2      = D2 & F1.Q;

        F2.OE  = D3;
        F1.C   = Clk;
        F1.OE  = !OE;

test_vectors   ([Clk,OE,INIT,D1,D2,D3] -> [ F1, F2])
                [.C., 0,  0 , 1, 1, 1] -> [ 1 , 0 ];
                [.C., 0,  0 , 0, 0, 1] -> [ 1 , 0 ];
                [.C., 0,  1 , 1, 1, 1] -> [ 0 , 1 ];
                [ 0 , 0,  0 , 0, 0, 1] -> [ 0 , 0 ];
end regfb