module dut( input fast_clk, slow_clk, input [3:0] waddr, raddr, input [3:0] wdata, input wen, output [3:0] rdata ); reg [3:0] mem[0:15]; reg [3:0] raddr_reg; always @(posedge fast_clk) begin if (wen) mem[waddr] <= wdata; end always @(posedge slow_clk) raddr_reg <= raddr; assign rdata = mem[raddr_reg]; endmodule