蜂鸣器——友谊地久天长

/ BELL.v
/********************************文件信息***********************************
**文件名字： BELL.v
**创建日期： 2008.07.10
**版本号： v1.0
**功能描述： 音乐播放器
**
****************************************************************************/
module BELL(
sys_clk,
beep
);
input sys_clk; //系统时钟48MHz
output beep; //蜂鸣器输出端
reg beep_r; //寄存器
reg[7:0] state; //乐谱状态机
reg[15:0] count;
reg[15:0] count_end;
reg[23:0] count1;
//乐谱参数:D=F/2K
parameter L_5=16'd61224, //低音5
L_6=16'd54545, //低音6
M_1=16'd45863, //中音1
M_2=16'd40865, //中音2
M_3=16'd36402, //中音3
M_5=16'd30612, //中音5
M_6=16'd27273, //中音6
H_1=16'd22956; //高音1
parameter TIME=12000000; //控制音的长短(250ms)
assign beep=beep_r; //输出音乐
/**********************************************************************************
**模块名称：分频器
**功能描述：计数分频
***********************************************************************************/
sys_clk)
begin
count<=count+1'b1; //计数器加1
if(count==count_end)
begin
count<=16'h0; //计数器清零
beep_r<=!beep_r; //输出取反
end
end
/************************************************************************************
**模块名称：曲谱
**功能描述：产生分频的系数并描述出曲谱
************************************************************************************/
sys_clk)
begin
if(count1count1=count1+1'b1;
else
begin
count1=24'd0;
if(state==8'd147)
state=8'd0;
else
state=state+1'b1;
case(state)
8'd0,8'd1: count_end=L_5;
8'd2,8'd3,8'd4,8'd5,8'd6,8'd7,8'd8:count_end=M_1;
8'd9,8'd10: count_end=M_3;
8'd11,8'd12,8'd13,8'd14: count_end=M_2;
8'd15: count_end=M_1;
8'd16,8'd17: count_end=M_2;
8'd18,8'd19: count_end=M_3;
8'd20,8'd21,8'd22,8'd23,8'd24: count_end=M_1;
8'd25,8'd26: count_end=M_3;
8'd27,8'd28: count_end=M_5;
8'd29,8'd30,8'd31,8'd32,8'd33: count_end=M_6;
8'd34,8'd35,8'd36,8'd37,8'd38: count_end=M_6;
8'd39,8'd40,8'd41,8'd42: count_end=M_5;
8'd43,8'd44,8'd45: count_end=M_3;
8'd46,8'd47: count_end=M_1;
8'd48,8'd49,8'd50,8'd51: count_end=M_2;
8'd52: count_end=M_1;
8'd53,8'd54: count_end=M_2;
8'd55,8'd56: count_end=M_3;
8'd57,8'd58,8'd59,8'd60: count_end=M_1;
8'd61,8'd62,8'd63: count_end=L_6;
8'd64,8'd65: count_end=M_5;
8'd66,8'd67,8'd68,8'd69: count_end=M_1;
8'd70,8'd71,8'd72,8'd73: count_end=M_1;
8'd74,8'd75: count_end=M_6;
8'd76,8'd77,8'd78,8'd79: count_end=M_5;
8'd80,8'd81,8'd82: count_end=M_3;
8'd83,8'd84: count_end=M_1;
8'd85,8'd86,8'd87,8'd88: count_end=M_2;
8'd89: count_end=M_1;
8'd90,8'd91: count_end=M_2;
8'd92,8'd93: count_end=M_6;
8'd94,8'd95,8'd96,8'd97: count_end=M_5;
8'd98,8'd99,8'd100: count_end=M_3;
8'd101,8'd102: count_end=M_5;
8'd103,8'd104,8'd105,8'd106: count_end=M_6;
8'd107,8'd108,8'd109,8'd110: count_end=M_6;
8'd111,8'd112: count_end=H_1;
8'd113,8'd114,8'd115,8'd116: count_end=M_5;
8'd117,8'd118,8'd119: count_end=M_3;
8'd120,8'd121: count_end=M_1;
8'd122,8'd123,8'd124,8'd125: count_end=M_2;
8'd126: count_end=M_1;
8'd127,8'd128: count_end=M_2;
8'd129,8'd130: count_end=M_3;
8'd131,8'd132,8'd133,8'd134: count_end=M_1;
8'd135,8'd136,8'd137: count_end=L_6;
8'd138,8'd139: count_end=M_5;
8'd140,8'd141,8'd142,8'd143: count_end=M_1;
8'd144,8'd145,8'd146,8'd147: count_end=M_1;
default:count_end=16'h0;
endcase
end
end
endmodule