樂曲演奏電路

1、9.10 樂曲演奏電路,音調(diào)控制,低音6 6MHz / 2 / 440Hz = 68189365 + 6818 = 16383,音長控制,全音符 1秒四分音符 4Hz八分音符 8Hz,[9.22]梁祝樂曲演奏電路/* clk50m 輸入時(shí)鐘，50MHzspeaker 驅(qū)動(dòng)揚(yáng)聲器的方波high, med, low 顯示高，中，低音 */,module song(clk5

2、0m, speaker, high, med, low);input clk50m;output reg speaker;output reg[3:0] high, med, low;,reg clk_6mhz; //產(chǎn)生音階的基準(zhǔn)時(shí)鐘reg clk_4hz; //控制音長的時(shí)鐘reg[13:0] divider, origin; //分頻計(jì)數(shù), 預(yù)置數(shù)wire carry; //分頻進(jìn)位reg[7:0] co

3、unter; //節(jié)拍計(jì)數(shù)reg[2:0] count8; //分頻計(jì)數(shù)reg[19:0] count20; //分頻計(jì)數(shù),//分頻得到6MHz時(shí)鐘always @(posedge clk50m) if(count8==7) begin count8<=0; clk_6mhz<=1; end else begin count8<=count8+1; clk_

4、6mhz<=0; end,//分頻得到4Hz時(shí)鐘always @(posedge clk_6mhz) if(count20==781250) begin clk_4hz<=~ clk_4hz; count20<=0; end else begin count20<=count20+1; end,//通過置數(shù)，改變分頻比always @(posedge clk_6mhz)

5、 if(divider==16383)begin carry<=1; divider<=origin; end elsebegin divider<=divider+1; carry=0; end,//得到驅(qū)動(dòng)揚(yáng)聲器的方波always @( posedge carry ) speaker <= ~speaker;,always @( posedge clk_4hz ) //

6、預(yù)置分頻比 case( { high, med, low } )'h001: origin <= 4915; //低音1'h002: origin <= 6168; //低音2…… 'h700: origin <= 14864; //高音7'h000: origin <= 16383; //休止符 endcaseen

7、d,// 分頻比預(yù)置'h003:origin <= 7281; // 低音3'h004:origin <= 7792; // 低音4'h005:origin <= 8730; // 低音5'h006:origin <= 9365; // 低音6'h007:origin <= 10310; // 低音7

8、'h010:origin <= 10647; // 中音1'h020:origin <= 11272; // 中音2'h030:origin <= 11831; // 中音3'h040:origin <= 12094; // 中音4 'h050:origin <= 12556; //

9、 中音5 'h060:origin <= 12974; // 中音6 'h070:origin <= 13346; // 中音7'h100:origin <= 13516; // 高音1'h200:origin <= 13829; //高音2 'h30

10、0:origin <= 14109; //高音3,//演奏樂譜always @(posedge clk_4hz)begin if(counter==134) counter<=0; //循環(huán)演奏 else counter<=counter+1;,case(counter) 0: {high, med, low} <= 'h003; //低3

11、1: {high, med, low} <= 'h003; //持續(xù)4拍 2: {high, med, low} <= 'h003; 3: {high, med, low} <= 'h003;…… 134: {high, med, low} <= 'h000; default: {high, me