基于fpga的電子琴說(shuō)明書(shū)

1、3.8程序設(shè)計(jì)流程圖 程序設(shè)計(jì)的流程圖如圖4所示。 開(kāi)始選擇播放模式還是彈奏模式？對(duì)時(shí)鐘信號(hào)進(jìn)行分頻得到4分音符的頻率等待用戶(hù)輸入按鍵等待用戶(hù)輸入樂(lè)曲編號(hào)通過(guò)對(duì)鍵盤(pán)的掃描確定按鍵的位置顯示樂(lè)曲編號(hào)根據(jù)所按鍵盤(pán)按鍵的位置，發(fā)出相應(yīng)的頻率根據(jù)樂(lè)曲的編號(hào)放出相應(yīng)的樂(lè)譜的頻率蜂鳴器發(fā)聲圖4 程序設(shè)計(jì)流程圖 本設(shè)計(jì)所選用的管腳接口如圖6所示： 圖6 管腳借口示意圖4、電子琴設(shè)計(jì)4.1樂(lè)曲播放功能設(shè)計(jì) 根據(jù)樂(lè)曲發(fā)聲的基本原理，樂(lè)曲播放模塊的設(shè)計(jì)思路是通過(guò)50MHz時(shí)鐘分頻的出1MHz信號(hào)，再對(duì)1MHz信號(hào)分頻，獲得音符節(jié)拍頻率，通過(guò)查表方式獲取音符分頻數(shù)作為音符分頻器模塊分頻的依據(jù)，將1MHz時(shí)鐘分頻獲得

2、合適的音符頻率，輸出至音頻功放模塊。電路結(jié)構(gòu)框圖如圖7所示。音頻輸出 4Hz時(shí)鐘系統(tǒng)頻率節(jié)拍控制分頻模塊音符分頻器樂(lè)曲選擇與長(zhǎng)度計(jì)數(shù)器樂(lè)曲存儲(chǔ) LED顯示模塊圖7 樂(lè)曲播放模塊結(jié)構(gòu)圖樂(lè)曲播放文件外部引腳及生成的符號(hào)如圖8所示。其中clk為 50MHz系統(tǒng)頻率，start為樂(lè)曲播放啟動(dòng)信號(hào)，sel為模塊選擇信號(hào)，choose為樂(lè)曲選擇信號(hào)，本設(shè)計(jì)設(shè)定檔sel為高電平時(shí)，模塊工作，out_sound1為音頻輸出信號(hào)，seg6為數(shù)碼管段碼輸出信號(hào).圖8 樂(lè)曲播放模塊符號(hào)4.1.1節(jié)拍控制分頻模塊 節(jié)拍控制分頻模塊主要用于產(chǎn)生樂(lè)曲的節(jié)拍，控制樂(lè)曲播放的節(jié)奏。50MHz的系統(tǒng)頻率經(jīng)過(guò)50次的分頻得到1M

3、Hz的頻率，再對(duì)1MHz信號(hào)進(jìn)行250000次分頻，可以得到4分音符持續(xù)時(shí)間的頻率，作為第二個(gè)進(jìn)程的時(shí)鐘信號(hào)，它的目的是控制每個(gè)音階之間的停頓時(shí)間，此處便是1/4=0.25s，其外部引腳及生成的符號(hào)如圖9所示:圖9 節(jié)拍控制分頻模塊符號(hào)其主要VHDL代碼如下所示：process(start,clk)begin if start='0'then clk_1MHz<='0' max_50 <= "000000" elsif clk'event and clk='1' then if max_50>= &q

4、uot;110001"then max_50<="000000" else max_50<=max_50+1; end if; if max_50="000000"then clk_1MHz<='1' else clk_1MHz<='0' end if; end if;end process;process(start,clk_1MHz)begin if start='0'then clk_4Hz<='0' max_250000 <= "

5、;0000000" elsif clk_1MHz'event and clk_1MHz='1' then if max_250000>= "1111111"then max_250000<="0000000" else max_250000<=max_250000+1; end if; if max_250000="0000000"then clk_4Hz<='1' else clk_4Hz<='0' end if; end if;end

6、process;4.1.3樂(lè)曲存儲(chǔ)模塊樂(lè)曲存儲(chǔ)模塊中存放的是樂(lè)曲各個(gè)音符的分頻值，假設(shè)系統(tǒng)頻率為1Mhz，根據(jù)表1中音符的頻率值，求得各音符的分頻系數(shù)如表2所示：表2 1MHz下簡(jiǎn)譜中音符的分頻系數(shù) 音名 分頻系數(shù) 音名 分頻系數(shù)音名 分頻系數(shù) 低音1 3823 中音11911 高音1956 低音23405 中音21703 高音2851 低音33034 中音31517 高音3758 低音42863 中音41432 高音4716 低音52551 中音51276 高音5638 低音62273 中音61137 高音6568 低音72025 中音71012 高音7506 其中存放的兩首樂(lè)曲分別是：第一

7、首揮著翅膀的女孩、第二首歌菊花臺(tái)。4.3頂層文件設(shè)計(jì) 采用原理圖的輸入方式，將上述樂(lè)曲播放和樂(lè)曲彈奏兩個(gè)文件分別生成符號(hào)文件，并在頂層文件中調(diào)用，電路圖如圖16所示。 圖16頂層文件輸入文件其主要VHDL代碼如下：Library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith.all;use ieee.std_logic_unsigned.all;entity top is port (clk0:in std_logic; start0:in std_logic; sel0:in std_logic; kbcol0:in st

8、d_logic_vector(0 to 3); kbrow0:out std_logic_vector(0 to 3); out_sound0:out std_logic; seg60:out std_logic_vector(0 to 6); choose0:in std_logic_vector(0 to 1) ); end;architecture one of top is component music port(clk:in std_logic; start:in std_logic; out_sound1:out std_logic; sel:in std_logic; choo

9、se:in std_logic_vector(0 to 1); seg6:out std_logic_vector(0 to 6) ); end component; component piano port (clk,start:in std_logic; kbcol:in std_logic_vector(0 to 3); kbrow:out std_logic_vector(0 to 3); out_sound2:out std_logic; sel:in std_logic );end component;component or22 port(a,b:in std_logic; c:

10、out std_logic);end component;signal g,h:std_logic;beginu1:music port map(clk=>clk0,start=>start0,choose=>choose0,sel=>sel0,out_sound1=>g,seg6=>seg60);u2:piano port map(kbcol=>kbcol0,kbrow=>kbrow0,clk=>clk0,sel=>sel0,start=>start0,out_sound2=>h);u3:or22 port map(a=

11、>g,b=>h,c=>out_sound0);end;6、總結(jié)本設(shè)計(jì)利用了硬件描述語(yǔ)言VHDL實(shí)現(xiàn)了電子琴的自動(dòng)演奏和鍵盤(pán)輸入發(fā)音的簡(jiǎn)易功能，經(jīng)過(guò)編程，綜合，仿真，下載，調(diào)試，電路板制作，最終做出了成品，測(cè)試情況也良好，能夠準(zhǔn)確實(shí)現(xiàn)音階的發(fā)音功能，可切換到樂(lè)曲播放存儲(chǔ)好的樂(lè)曲，可根據(jù)需要更改程序從而實(shí)現(xiàn)不同樂(lè)曲的存儲(chǔ)，也可以通過(guò)在4*4鍵盤(pán)上的按鍵來(lái)彈奏出不同的音調(diào)。在設(shè)計(jì)過(guò)程，由于對(duì)音樂(lè)的知識(shí)不夠熟悉，所以沒(méi)有實(shí)現(xiàn)電子琴那么完美的音樂(lè)。在本系統(tǒng)設(shè)計(jì)調(diào)試過(guò)程中，軟件和硬件都出現(xiàn)了一些小錯(cuò)誤。例如在焊接電路時(shí)，由于不夠細(xì)心，把共陽(yáng)極數(shù)碼管的公共端焊接到地端上了；在把外圍電路板上

12、連接芯片時(shí)，由于選錯(cuò)了一兩個(gè)管腳，而導(dǎo)致結(jié)果與預(yù)期的不同，浪費(fèi)了很多時(shí)間找原因。在軟硬件結(jié)合調(diào)試時(shí)，自動(dòng)彈奏音樂(lè)時(shí)出現(xiàn)了噪音現(xiàn)象，經(jīng)過(guò)了仔細(xì)檢查所有程序，發(fā)現(xiàn)了問(wèn)題是出現(xiàn)在分頻模塊的編寫(xiě)上，所用芯片的工作頻率是50MHz，而程序中我的工作頻率卻設(shè)定為1MHz，于是我在播放模塊中增加多一個(gè)50分頻的程序，從而把問(wèn)題解決了。61樂(lè)曲播放模塊總結(jié)如果想要播放更多首樂(lè)曲的話(huà)，只需要增加choose的相應(yīng)位數(shù)，和增加存儲(chǔ)模塊中的樂(lè)曲數(shù)。比如要播放8首樂(lè)曲，則可以設(shè)置choose：in std_logic_vector(2 downto 0)，其中“000”代表第一首，“001”代表第二首，“010”代表

13、第三首，“011”代表第五首，“100”代表第六首，“101代表第七首，“111”代表第八首。想要設(shè)置更多樂(lè)曲，可根據(jù)需要設(shè)定好合適的choose位數(shù)。另外，樂(lè)曲播放模塊還可以采用查表方式來(lái)播放存儲(chǔ)的樂(lè)曲，即在ROM中寫(xiě)入所要播放音樂(lè)的全部頻率，通過(guò)編程來(lái)一一查找每一個(gè)頻率，從而實(shí)現(xiàn)樂(lè)曲的播放。62樂(lè)曲彈奏模塊總結(jié)除了采用4*4鍵盤(pán)作為按鍵輸入外，還可以選擇3*7鍵盤(pán)，采用3*7鍵盤(pán)的話(huà)，就可以設(shè)置每一個(gè)按鍵代表一個(gè)音符，也就是說(shuō)21個(gè)音符都可以有不同的按鍵來(lái)彈奏，這樣在彈奏樂(lè)曲時(shí)，在選擇高、中、低音轉(zhuǎn)換時(shí)，就不需要額外的按鍵，而且把按鍵的利用率達(dá)到100%,而在4*4鍵盤(pán)中，有6個(gè)按鍵是沒(méi)用

14、的，利用率比3*7鍵盤(pán)低。和4*4鍵盤(pán)掃描類(lèi)似，3*7鍵盤(pán)可以采用掃描3個(gè)列檢測(cè)7個(gè)行，也可以采用掃描7個(gè)列檢測(cè)3個(gè)行，這兩種只是編程方式不同，道理一樣。如果采用掃描7個(gè)列檢測(cè)3個(gè)行的話(huà)，列掃描信號(hào)由列引腳“列1列2列3列4列5列6列7”進(jìn)入鍵盤(pán)，以1111110、1111101、1111011、1110111、1101111、1011111、0111111的順序每次掃描其中的一列，然后讀取行引腳的電平信號(hào)就可以判斷是哪個(gè)按鍵被按下。例如，當(dāng)掃描信號(hào)為1111110時(shí)表示正在掃描列7，如果該列沒(méi)按鍵按下，則由行信號(hào)讀出的值為1111111；反之，當(dāng)?shù)诙杏邪存I按下，則由行信號(hào)“行1行2行3”讀

15、出的值為101，鍵盤(pán)的列選擇信號(hào)以及行選擇信號(hào)均為低電平有效。附錄一 不工作時(shí) 播放一首樂(lè)曲時(shí)，數(shù)碼管也顯示1 播放第二首樂(lè)曲時(shí)，數(shù)碼管也顯示2 外圍電路板原理圖附錄二程序：頂層文件：Library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith.all;use ieee.std_logic_unsigned.all;entity top is port (clk0:in std_logic; start0:in std_logic; sel0:in std_logic; kbcol0:in std_logic_vector(

16、0 to 3); kbrow0:out std_logic_vector(0 to 3); out_sound0:out std_logic; seg60:out std_logic_vector(0 to 6); choose0:in std_logic_vector(0 to 1) ); end;architecture one of top is component music port(clk:in std_logic; start:in std_logic; out_sound1:out std_logic; sel:in std_logic; choose:in std_logic

17、_vector(0 to 1); seg6:out std_logic_vector(0 to 6) ); end component; component piano port (clk,start:in std_logic; kbcol:in std_logic_vector(0 to 3); kbrow:out std_logic_vector(0 to 3); out_sound2:out std_logic; sel:in std_logic );end component;component or22 port(a,b:in std_logic; c:out std_logic);

18、end component;signal g,h:std_logic;beginu1:music port map(clk=>clk0,start=>start0,choose=>choose0,sel=>sel0,out_sound1=>g,seg6=>seg60);u2:piano port map(kbcol=>kbcol0,kbrow=>kbrow0,clk=>clk0,sel=>sel0,start=>start0,out_sound2=>h);u3:or22 port map(a=>g,b=>h,c

19、=>out_sound0);end;樂(lè)曲播放模塊：Library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith.all;use ieee.std_logic_unsigned.all;entity music isgeneric(mid8:integer range 1000 to 4000:= 1911;mid9:integer range 1000 to 4000:= 1703;mid10:integer range 1000 to 4000:= 1517;mid11:integer range 1000 to 4

20、000:= 1432;mid12:integer range 1000 to 4000:= 1276;mid13:integer range 1000 to 4000:= 1137;mid14:integer range 1000 to 4000:= 1012;low1:integer range 1000 to 4000:= 3823;low2:integer range 1000 to 4000:= 3405;low3:integer range 1000 to 4000:= 3034;low4:integer range 1000 to 4000:= 2863;low5:integer

21、range 1000 to 4000:= 2551;low6:integer range 1000 to 4000:= 2273;low7:integer range 1000 to 4000:= 2025;high15:integer range 100 to 4000:= 956;high16:integer range 100 to 4000:= 851;high17:integer range 100 to 4000:= 758;high18:integer range 100 to 4000:= 716;high19:integer range 100 to 4000:= 638;h

22、igh20:integer range 100 to 4000:= 568;high21:integer range 100 to 4000:= 506);port(clk:in std_logic; start:in std_logic; out_sound1:out std_logic; sel:in std_logic; choose:in std_logic_vector(0 to 1) seg6:out std_logic_vector(0 to 6) );end music;architecture behav of music issignal clk_4Hz : std_log

23、ic;signal clk_1MHz : std_logic;signal count : integer range 0 to 4096;signal freq : integer range 0 to 4096;signal counter : integer range 0 to 150;signal max_250000 : std_logic_vector(17 downto 0);signal tmp:integer range 0 to 100;signal rset:std_logic;signal out_sound12:std_logic;signal out_sound1

24、1:std_logic;signal max_50 : std_logic_vector(5 downto 0);beginprocess(start,clk)begin if start='0'then clk_1MHz<='0' max_50 <= "000000" elsif clk'event and clk='1' then if max_50>= "110001"then max_50<="000000" else max_50<=max

25、_50+1; end if; if max_50="000000"then clk_1MHz<='1' else clk_1MHz<='0' end if; end if;end process;process(start,clk_1MHz)begin if start='0'then clk_4Hz<='0' max_250000 <= "0000000" elsif clk_1MHz'event and clk_1MHz='1' then

26、if max_250000>= "1111111"then max_250000<="0000000" else max_250000<=max_250000+1; end if; if max_250000="0000000"then clk_4Hz<='1' else clk_4Hz<='0' end if; end if;end process; process(choose,clk) -選歌信號(hào)檢測(cè)進(jìn)程：variable a:std_logic_vector(0 t

27、o 1);variable b:std_logic_vector(0 to 1);variable c:std_logic_vector(0 to 1);beginif clk'event and clk='1' thenb:=a;a:=choose;c:= b - a;end if;if c="00" then rset<='0'else rset<='1'end if;end process; process(clk_4Hz,rset,start,choose) beginif start='0

28、' then tmp<=0;elsif rset='1' then tmp<=0;elsif (clk_4Hz'event and clk_4Hz='1') then if tmp>=56 then tmp<=0;elsetmp<=tmp+1; end if;end if;case choose iswhen "01" => counter<=tmp;seg6<="1111001"when "10" => counter<=tm

29、p+57;seg6<="0100100"when others => counter<=0;seg6<="1000000"end case;end process; process(counter)begin case counter is when 0=>freq<=0; when 1=>freq<=mid10; when 2=>freq<=mid10; when 3=>freq<=mid11; when 4=>freq<=mid12; when 5=>freq&

30、lt;=mid12; when 6=>freq<=mid8; when 7=>freq<=mid9; when 8=>freq<=mid10; when 9=>freq<=mid10; when 10=>freq<=mid10; when 11=>freq<=mid11; when 12=>freq<=mid12; when 13=>freq<=mid12; when 14=>freq<=mid9; when 15=>freq<=mid10; when 16=>freq

31、<=mid11; when 17=>freq<=mid11; when 18=>freq<=mid11; when 19=>freq<=mid10; when 20=>freq<=mid8; when 21=>freq<=mid8; when 22=>freq<=mid11; when 23=>freq<=mid10; when 24=>freq<=mid11; when 25=>freq<=mid11; when 26=>freq<=low6; when 27=>

32、;freq<=mid8; when 28=>freq<=mid9; when 29=>freq<=mid9; when 30=>freq<=mid8; when 31=>freq<=mid9; when 32=>freq<=mid10; when 33=>freq<=mid10; when 34=>freq<=mid10; when 35=>freq<=mid11; when 36=>freq<=mid12; when 37=>freq<=mid12; when 38=

33、>freq<=mid13; when 39=>freq<=mid14; when 40=>freq<=high15; when 41=>freq<=high15; when 42=>freq<=mid10; when 43=>freq<=mid11; when 44=>freq<=mid12; when 45=>freq<=mid12; when 46=>freq<=mid9; when 47=>freq<=mid10; when 48=>freq<=mid11;

34、 when 49=>freq<=mid10; when 50=>freq<=mid11; when 51=>freq<=high15; when 52=>freq<=high15; when 53=>freq<=high15; when 54=>freq<=mid9; when 55=>freq<=mid10; when 56=>freq<=mid11; when 57=>freq<=high15; when 58=>freq<=mid10; when 59=>freq

35、<=mid10; when 60=>freq<=mid10; when 61=>freq<=mid9; when 62=>freq<=mid10; when 63=>freq<=0; when 64=>freq<=0; when 65=>freq<=0; when 66=>freq<=mid10; when 67=>freq<=mid12; when 68=>freq<=mid10; when 69=>freq<=mid9; when 70=>freq<=m

36、id10; when 71=>freq<=mid10; when 72=>freq<=mid10; when 73=>freq<=mid10; when 74=>freq<=mid8; when 75=>freq<=mid8; when 76=>freq<=mid8; when 77=>freq<=mid9; when 78=>freq<=mid10; when 79=>freq<=mid12; when 80=>freq<=mid10; when 81=>freq&l

37、t;=mid10; when 82=>freq<=mid9; when 83=>freq<=mid9; when 84=>freq<=mid9; when 85=>freq<=mid8; when 86=>freq<=mid9; when 87=>freq<=mid9; when 88=>freq<=mid9; when 89=>freq<=mid9; when 90=>freq<=mid10; when 91=>freq<=mid10; when 92=>freq&l

38、t;=mid10; when 93=>freq<=mid12; when 94=>freq<=mid13; when 95=>freq<=mid12; when 96=>freq<=mid12; when 97=>freq<=mid12; when 98=>freq<=mid13; when 99=>freq<=mid12; when 100=>freq<=mid12; when 101=>freq<=mid10; when 102=>freq<=mid12; when 10

39、3=>freq<=mid12; when 104=>freq<=mid12; when 105=>freq<=low5; when 106=>freq<=mid10; when 107=>freq<=mid10; when 108=>freq<=mid9; when 109=>freq<=mid9; when 110=>freq<=mid12; when 111=>freq<=mid12; when 112=>freq<=mid10; when 113=>freq<

40、;=mid9; when others=>freq<=0; end case;end process;process(clk_1MHz,start,sel)begin if sel='0'then out_sound12<='0' else if start='0'then count<=0; out_sound12<='0' elsif clk_1MHz'event and clk_1MHz='1'then if freq=0 then out_sound12<=

41、9;0' elsif count=0 then count<=freq; out_sound12<='1' else count<=count-1; out_sound12<='0' end if; end if; end if;end process;PROCESS(out_sound12) -二分頒，方波輸出BEGIN IF out_sound12 'EVENT AND out_sound12='1' THEN out_sound11 <=NOT out_sound11; END IF; out_

42、sound1<=out_sound11;END PROCESS;end behav; 樂(lè)曲彈奏模塊：Library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith.all;use ieee.std_logic_unsigned.all;entity piano isport (clk,start:in std_logic; kbcol:in std_logic_vector(0 to 3); kbrow:out std_logic_vector(0 to 3); out_sound2:out std_logic; sel

43、:in std_logic );end entity;architecture piano of piano issignal state:std_logic_vector(2 downto 0);signal clk1:std_logic;signal clk_1MHz : std_logic;signal d:std_logic_vector(4 downto 0);signal snote:std_logic_vector(4 downto 0);signal sscal:std_logic_vector(1 downto 0);signal cnt,scnt:std_logic_vec

44、tor(9 downto 0);signal ctrln:std_logic_vector(2 downto 0);signal count,freq:integer range 0 to 4096;signal out_sound22:std_logic;signal out_sound21:std_logic;signal d0,d1,d2,d3,d_reg:std_logic_vector(4 downto 0);signal max_50 : std_logic_vector(5 downto 0);constant low1:integer:=3822; constant low2:

45、integer:=3405;constant low3:integer:=3034;constant low4:integer:=2863;constant low5:integer:=2551;constant low6:integer:=2273;constant low7:integer:=2025;constant mid1:integer:=1911;constant mid2:integer:=1703;constant mid3:integer:=1517;constant mid4:integer:=1432;constant mid5:integer:=1276;consta

46、nt mid6:integer:=1137;constant mid7:integer:=1012;constant high1:integer:=956;constant high2:integer:=851;constant high3:integer:=758;constant high4:integer:=716;constant high5:integer:=638;constant high6:integer:=568;constant high7:integer:=506;constant stop:integer:=0;beginprocess(start,clk)begin

47、if start='0'then clk_1MHz<='0' max_50 <= "000000" elsif clk'event and clk='1' then if max_50>= "110001"then max_50<="000000" else max_50<=max_50+1; end if; if max_50="000000"then clk_1MHz<='1' else clk_1MHz

48、<='0' end if; end if;end process;clk1<=cnt(9);process(clk_1MHz)beginif clk_1MHz'event and clk_1MHz='1'thencnt<=cnt+1;end if;end process;d<=d0 or d1 or d2 or d3;process(clk1)beginif clk1'event and clk1='1'thencase state iswhen "000"=>kbrow<=

49、"1110"state<="001" case kbcol is when"0111"=>d0<="11111" when"1011"=>d0<="11011" when"1101"=>d0<="10111" when"1110"=>d0<="10011" when others=>d0<="00000" end

50、 case;when"001"=>kbrow<="1101"state<="010" case kbcol is when"0111"=>d1<="11110" when"1011"=>d1<="11010" when"1101"=>d1<="10110" when"1110"=>d1<="10010" when

51、 others=>d1<="00000" end case;when"010"=>kbrow<="1011"state<="011" case kbcol is when"0111"=>d2<="11101" when"1011"=>d2<="11001" when"1101"=>d2<="10101" when"1110

52、"=>d2<="10001" when others=>d2<="00000" end case;when"011"=>kbrow<="0111"state<="100" case kbcol is when"0111"=>d3<="11100" when"1011"=>d3<="11000" when"1101"=>

53、;d3<="10100" when"1110"=>d3<="10000" when others=>d3<="00000" end case; when"100"=>state<="000" if d="00000"then d_reg<=d; if scnt=100 then snote<="00000" else scnt<=scnt+1; end if; else scn

54、t<="0000000000" if d /= d_reg then d_reg<=d; if d>="10001"and d<="10111"then snote<=sscal&d(2 downto 0); elsif d="11010"then sscal<="11" elsif d="11011"then sscal<="10" elsif d="11100"then sscal&

55、lt;="01" end if; end if; end if;when others=>state<="000"end case;-end if;end if;end process;process(snote)begin case snote is when"01001"=>freq<=low1; when"01010"=>freq<=low2; when"01011"=>freq<=low3; when"01100"=&g

56、t;freq<=low4; when"01101"=>freq<=low5; when"01110"=>freq<=low6; when"01111"=>freq<=low7; when"10001"=>freq<=mid1; when"10010"=>freq<=mid2; when"10011"=>freq<=mid3; when"10100"=>freq<=mi

57、d4; when"10101"=>freq<=mid5; when"10110"=>freq<=mid6; when"10111"=>freq<=mid7; when"11001"=>freq<=high1; when"11010"=>freq<=high2; when"11011"=>freq<=high3; when"11100"=>freq<=high4; when"11101"=>freq<=high5; when"11110"=>freq<=high6; when"11111&quo