tests/opt/opt_dff_clk.ys

   1 ### Never-toggling CLK removal.
   2
   3 read_verilog -icells <<EOT
   4
   5 module top(...);
   6
   7 input EN;
   8 input [1:0] D;
   9 (* init = 18'h15555 *)
  10 output [17:0] Q;
  11 input SRST;
  12 input ARST;
  13 input [1:0] CLR;
  14 input [1:0] SET;
  15
  16 $dff #(.CLK_POLARITY(1'b1), .WIDTH(2)) ff0 (.CLK(1'b0), .D(D), .Q(Q[1:0]));
  17 $dffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .WIDTH(2)) ff1 (.CLK(1'b1), .EN(EN), .D(D), .Q(Q[3:2]));
  18 $adff #(.CLK_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff2 (.CLK(1'bx), .ARST(ARST), .D(D), .Q(Q[5:4]));
  19 $adffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b0), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff3 (.CLK(1'b0), .EN(EN), .ARST(ARST), .D(D), .Q(Q[7:6]));
  20 $sdff #(.CLK_POLARITY(1'b1), .SRST_POLARITY(1'b1), .SRST_VALUE(2'h2), .WIDTH(2)) ff4 (.CLK(1'b1), .SRST(SRST), .D(D), .Q(Q[9:8]));
  21 $sdffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b1), .SRST_VALUE(2'h2), .WIDTH(2)) ff5 (.CLK(1'bx), .EN(EN), .SRST(SRST), .D(D), .Q(Q[11:10]));
  22 $sdffce #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b1), .SRST_VALUE(2'h2), .WIDTH(2)) ff6 (.CLK(1'bx), .EN(EN), .SRST(SRST), .D(D), .Q(Q[13:12]));
  23 $dffsr #(.CLK_POLARITY(1'b1), .CLR_POLARITY(1'b1), .SET_POLARITY(1'b0), .WIDTH(2)) ff7 (.CLK(1'b1), .SET(SET), .CLR(CLR), .D(D), .Q(Q[15:14]));
  24 $dffsre #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b0), .CLR_POLARITY(1'b1), .SET_POLARITY(1'b0), .WIDTH(2)) ff8 (.CLK(1'bx), .EN(EN), .SET(SET), .CLR(CLR), .D(D), .Q(Q[17:16]));
  25
  26 endmodule
  27
  28 EOT
  29
  30 design -save orig
  31
  32 equiv_opt -undef -assert -multiclock opt_dff -keepdc
  33 design -load postopt
  34 select -assert-count 2 t:$dlatch
  35 select -assert-count 2 t:$sr
  36 select -assert-none t:$dlatch t:$sr %% %n t:* %i
  37
  38 design -load orig
  39 simplemap
  40
  41 equiv_opt -undef -assert -multiclock opt_dff -keepdc
  42 design -load postopt
  43 select -assert-count 4 t:$_DLATCH_?_
  44 select -assert-count 4 t:$_SR_??_
  45 select -assert-none t:$_DLATCH_?_ t:$_SR_??_ %% %n t:* %i