| module top |
| ( |
| input x, |
| input y, |
| input cin, |
| |
| output reg A, |
| output cout |
| ); |
| parameter X = 1; |
| wire o; |
| |
| `ifndef BUG |
| always @(posedge cin) |
| A <= o; |
| |
| assign cout = cin? y : x; |
| |
| middle u_mid1 (.x(x),.o(o),.y(1'b0)); |
| middle u_mid2 (.x(x),.o(o),.y(1'b1)); |
| middle u_mid3 (.x(x),.o(o),.y(1'bX)); |
| middle u_mid4 (.x(x),.o(o),.y(1'bX)); |
| `else |
| assign {cout,A} = cin - y * x; |
| `endif |
| |
| endmodule |
| |
| module middle |
| ( |
| input x, |
| input y, |
| output o |
| ); |
| |
| urtl u_urtl (.x(x),.o(o),.y(y)); |
| endmodule |
| |
| module urtl |
| ( |
| input x, |
| input y, |
| output o |
| ); |
| |
| assign o = x + y; |
| endmodule |
