module counter4bit_2clock(clk0, rst0, clk1, rst1, q0, q1); input clk0; input rst0; output [3:0] q0; reg [3:0] q0; input clk1; input rst1; output [3:0] q1; reg [3:0] q1; always @ (posedge clk0) begin if(rst0) q0 <= 4'b0000; else q0 <= q0 + 1; end always @ (posedge clk1) begin if(rst1) q1 <= 4'b0000; else q1 <= q1 + 1; end endmodule