module demo_sound1( input clock, output [7:0]key_code, input k_tr ); reg [15:0]tmp; wire[15:0]tmpa; reg tr; reg [15:0]step; wire[15:0]step_r; reg [15:0]TT; reg[5:0]st; reg go_end; ////////Music-processing//////// always @(negedge k_tr or posedge clock) begin if (!k_tr) begin step=0; st=0; tr=0; end else if (steptmpa)go_end=1; else tmp=tmp+1; end assign key_code=(tmp<(tmpa-1))?key_code1:8'hf0; endmodule