examples/cmos/cmos_cells.v

   1
   2 module BUF(A, Y);
   3 input A;
   4 output Y;
   5 assign Y = A;
   6 endmodule
   7
   8 module NOT(A, Y);
   9 input A;
  10 output Y;
  11 assign Y = ~A;
  12 endmodule
  13
  14 module NAND(A, B, Y);
  15 input A, B;
  16 output Y;
  17 assign Y = ~(A & B);
  18 endmodule
  19
  20 module NOR(A, B, Y);
  21 input A, B;
  22 output Y;
  23 assign Y = ~(A | B);
  24 endmodule
  25
  26 module DFF(C, D, Q);
  27 input C, D;
  28 output reg Q;
  29 always @(posedge C)
  30         Q <= D;
  31 endmodule
  32
  33 module DFFSR(C, D, Q, S, R);
  34 input C, D, S, R;
  35 output reg Q;
  36 always @(posedge C, posedge S, posedge R)
  37         if (S)
  38                 Q <= 1'b1;
  39         else if (R)
  40                 Q <= 1'b0;
  41         else
  42                 Q <= D;
  43 endmodule
  44