// // Simple D-register behavioural model // To be used in Xtal_startup testbench // Has small delay to show a-sync behaviour // module DregNegSet( input clk, input set_n, input I, output reg Q ); begin always @(posedge clk or negedge set_n) if (!set_n) Q <= #1 1'b1; else Q <= #1 I; end endmodule // Dreg