/////////////////////////////////////////////////////////////////////////////module clkgen(phi1, phi2);///////////////////////////////////////////////////////////////////////////// output        phi1,           // Two-phase non-overlapping clocks                phi2;  reg           phi1,                phi2;          // Start with both clocks low  initial    begin      phi1 = 0;      phi2 = 0;    end  // Generate two-phase non-overlapping clock waveforms  always    begin      #20 phi1 = 0; // 1ns scale works        #5 phi2 = 1;      #20 phi2 = 0;       #5 phi1 = 1;    end            endmodule