實驗四 8421BCD碼加法乘法運算

QuartusII基本應(yīng)用8421BCD碼加法乘法運算、實驗?zāi)康挠迷韴D輸入法實現(xiàn)2個8421BCD的和，用數(shù)碼管顯示被加數(shù)、加數(shù)和加的結(jié)果。每個8421BCD碼由4個撥碼開關(guān)作為輸入，總共需要8個撥碼開關(guān)。輸出要求在開發(fā)板數(shù)碼管上顯示輸入的2個8421BCD碼和加的結(jié)果。用VHDL或VerilogHDL實現(xiàn)2個8421BCD的乘積，用數(shù)碼管顯示被乘數(shù)、乘數(shù)和乘的結(jié)果。每個8421BCD碼由4個撥碼開關(guān)作為輸入,總共需要8個撥碼開關(guān)。輸出要求在開發(fā)板數(shù)碼管上顯示輸入的2個8421BCD碼和乘的結(jié)果。二、實驗設(shè)備1、計算機(QuartusII)2、DE0開發(fā)板三、實驗原理BCD代碼。Binary-CodedDecimal，簡稱BCD,稱BCD碼或二轉(zhuǎn)十進制代碼，亦稱二進碼十進數(shù)。是一種二進制的數(shù)字編碼形式，用二進制編碼的十進制代碼。這種編碼形式利用了四個位元來儲存一個十進制的數(shù)碼，使二進制和十進制之間的轉(zhuǎn)換得以快捷的進行。這種編碼技巧，最常用于會計系統(tǒng)的設(shè)計里，因為會計制度經(jīng)常需要對很長的數(shù)字串作準(zhǔn)確的計算。相對于一般的浮點式記數(shù)法，采用BCD碼，既可保存數(shù)值的精確度，又可免卻使電腦作浮點運算時所耗費的時間。此外，對于其他需要高精確度的計算，BCD編碼亦很常用。8421碼是BCD代碼中最常用的一種。在這種編碼方式中每一位二值代碼的1都是代表一個固定數(shù)值，把每一位的1代表的十進制數(shù)加起來，得到的結(jié)果就是它所代表的十進制數(shù)碼。由于代碼中從左到右每一位的1分別表示8,4,2，1,所以把這種代碼叫做8421代碼。每一位的1代表的十進制數(shù)稱為這一位的權(quán)。8421碼中的每一位的權(quán)是固定不變的，它屬于恒權(quán)代碼。1.兩個8I21BCD數(shù)的和兩個S421BCD碼相加，最大為1爲(wèi)超過9后應(yīng)產(chǎn)生進位'但芯片在15以內(nèi)不產(chǎn)匸進位，超過15產(chǎn)丄進位，但是和不足逢十進篤所以必須加以修正;兩個BCD碼相加必須有一部分組成:第一部分進行相加;第.1部分產(chǎn)宀修正控制信號；第：〔部分完成加6修正；〔3)第、第〔部分由兩片全加器完成.由第1部分顯示判別信號，當(dāng)有進位輸出吋|或者利數(shù)在10^15的情況卜嚴(yán)生控制信號F：F—爭出血+竽苗&)+爭￡気—￡比瓦瓦)-鳥瓦隔--CO-S^S.+S^

A3YOA2Y1A1Y2A3YOA2Y1A1Y2A07447Y3LTY4RBOY6biY7RBI用7447驅(qū)動共陽極七波段數(shù)碼管的連接方法Figuie2在Figme2管將全部變?yōu)楦唠娖?；半時應(yīng)置L?f=l；BI/RBO為火燈輸入/輸出控制中：燈測試輸j入LT：LT=Olid'-a.b,c,d.e.￡gL個顯示端.主要進行務(wù)位數(shù)碼顯示系統(tǒng)的滅零控制；滅零輸入融；為了將不希堂顯示的0熄滅(在本次實驗山忖要是為了將當(dāng)輸出的和或乘積為個位數(shù)時.使得十位上的0熄滅人Table1共I打扱七波段數(shù)碼件顯小的丫符代碼占顯示字符0173斗56789滅零代碼(H)407924301912037800IS7F8421BCD碼乘法運算把二進制數(shù)中的“0”和“1”全部當(dāng)成是十進制數(shù)中的“0”和“1”即可。根據(jù)十進制數(shù)中的乘法運算知道，任何數(shù)與“0”相乘所得的積均為“0”，這一點同樣適用于二進制數(shù)的乘法運算。只有“1”與“1”相乘才等于“1”。乘法運算步驟：（1）首先是乘數(shù)的最低位與被乘數(shù)的所有位相乘，因為乘數(shù)的最低位為“0”，根據(jù)以上原則可以得出，它與被乘數(shù)（1110）的所有位相乘后的結(jié)果都為“0”。（2）再是乘數(shù)的倒數(shù)第二位與被乘數(shù)的所有位相乘，因為乘數(shù)的這一位為“1”，根據(jù)以上原則可以得出，它與被乘數(shù)（1110）的高三位相乘后的結(jié)果都為“1”，而于最低位相乘后的結(jié)果為“0”。（3）再是乘數(shù)的倒數(shù)第三位與被乘數(shù)的所有位相乘，同樣因為乘數(shù)的這一位為“1”，處理方法與結(jié)果都與上一步的倒數(shù)第二位一樣，不再贅述。（4）最后是乘數(shù)的最高位與被乘數(shù)的所有位相乘，因為乘數(shù)的這一位為“0”，所以與被乘數(shù)（1110）的所有位相乘后的結(jié)果都為“0”。（5）然后再按照前面介紹的二進制數(shù)加法原則對以上四步所得的結(jié)果按位相加，結(jié)果得到（1110）X（0110）=（1010100）四、實驗結(jié)果仿真展示BCD8421加法仿真仿真原理圖仿真波形（二進制）SimuhtionWaveformsSinulatLanmudsruictinial蕊肋terTiineRar;15.525ns寸勺Points：42?,B3nsInter囘占tatEnd:0ALf0SBIJO田AjisjLiyK40□Biii^lkjrK40[+]CO_d)sp^-tyK7國S^iispB_yH40057723——禪亙齣-樹亙祿無風(fēng)詁A%T結(jié)果顯示SimuhtionWaveformsSiirulationmoieFuhgtional希MatteiTtfiksBar14.051LIEIrJervdl.U.07iriHarneValue21.5ns0o,ui|j]4ata_in_lHI0dst4_in_l_diiplay[*|laiti_i.n_2_displayBiat^_outjCO_di.splay13JspalyI：0

t：0

K抑140I4CK404G40713^YITWx_.7FL7F37FT19結(jié)果顯示（注,在本次仿真中￡的字符代碼為02H.9的字符代碼為10H,無滅零操作｝clatainl0123456了89datainldisplay40792430191202780010datai.n20123456了89datain1.display40792430191202780010(kitaoutCOdispay40404040792430190200dataoutC00000123彳68dataoutSdispay4079】g10021202101979dataoutS014916253649648L兩個實驗經(jīng)硬件測試均與仿真相符合，達(dá)到實驗要求。

五、實驗心得體會本次實驗中，我們隊兩個8421BCD數(shù)的和的邏輯電路以及工作原理有了更深的理解與掌握，但是對于VHDL語言的具體編程方法還沒有深刻理解，對兩個數(shù)的乘積的編程用了枚舉法，下次實驗中要對該方法進行更深刻的研究。附：兩個8421BCD數(shù)的乘積VHDL代碼LIBRARYIEEE;USEIEEE.STD_LOGIC_1164.ALL;ENTITYiniil4aISPORT(data_iii:INSTD_LOGIC_\TCTOR("DOWNTO0):data_out:OUTSTD_LOGIC_VECTOR(茁DOWNTO0)):ENDnnil4a:ARCHITECTUREfenOFnud4aISBEGINPROCESS(datain)BEGINCASEdataiiiISWHEN1,00000000，T=>data_out<=1pl000000l00000010000001000000，TiWHEN^OOOOOOOl^Xia-rfl-OUt^'lOOOOOOl11100110000001000000，r:WHEN^OTOOOOlO'^data-OU^'lOOOOOOOlOOlOOlOOOTOOlOO^OOO^WHEN1,00000011匚>data_out<：=ri10000000110000100000010000001':WHEN唱0000100"=>缶怕_51匕=叫00000000110011.000000100000卩：WHEN1,OOOOOlOrr=>data_out<=1，lOOOOOOOOlOOlOlOOOOOOlOOOOOO，T:U^HEN^OOOOOllO^data-OuK^l000000000001010000001000000，r:U^HEN^OOOOOlir^data-OUt^"1000000111100010000001000000iP:WHEN^OOOOlOOO'^Xlataout^'lOOOOOOOOOOOOOlOOOOOOlOOOOOO1^WHEN町000100「=Hbta_outv」l0000000010000100000010OOOOCT：WHEN”0001000(r=Aeh_om<i1111001100000010000001OOOOOO11;WHENn00010001,f=>dataout<=H1111001111100110000001111001°;WHEN”00010010”=Adata_out<i1111001010010010000000100100”;WHEN^OOOlOOir^Xlataout<illll001011000010000000110000‘:WHENH00010100,,=>data_out<=H11110010011001100000000110011*;WHEN”00010101M=>data_out<=H1111001001001010000000010010”;WHEN”00010110,,=>data_out<=H1111001000001010000000000010H;WHEN”0001011T』>data_ouV”1111001111100010000001111000“；WHEN"OOOllOOO^Xlataoiit<=H111100100000001OOOOOOOOOOOOO*1;WHEN”0001100r,=>data_ont<=H1111001001000010000000010000n;WHENH00100000M=>data_om<=n0100100100000010000001000000，1;WHEN”00100001n=>data_oiit<=nO100100111100110000000100100”;WHEN”00100010”=AdntJi_outv=”0100100010010010000000011001”：WHEN”00100011n=>dataout<=nO100100011000010000000000010n:WHENn00100100n=Xlataout<=n0100100001100110000000000000n;WHEN”00100101joutv=”0100100001001011110011000000";WHEN叫0100110”=>dataout<=nO100100000001011110010100100M;WHEN?'00100111,'=>data_ont<=',0100100111100011110010011001,';WHEN1tOOlOlOOOM=>dataout<=n0100100000000011110010000010M;WHEN1,00101001M=>data_out<=nO100100001000011110010000000";WHEN?'0011000(r=>data_omvi011000010000001000000100000(r：WHENw,00110001M=>dataout<=H0110000111100110000000110000”：WHENi,00110010n=>dataout<=H0110000010010010000000000010f,;WHEN??00110011“二〉datjou仁=“0110000011000010000000010000”;WHEN"OOllOlOOM=>data_out<=nO110000001100111110010100100u;WHEN^00110101H=>data_out<=H0110000001001011110010010010H:WHEN"00110110n=>dataout<=”0110000000001011110010000000”：WHEN1,00110111n=>clata_out<=”0110000111100001001001111001n;WHEN"00111000H=>data_out<="Oil000000000000100100001100l,r;WHEN^00111001H=>dataout<=”0110000001000001001001111000”：WHEN“01000000”=>data_out<i0011001100000010000001000000n;WHENH01000001”=>data_out<=“0011001111100110000000011001”；WHEN“010000LO”=>data_QUt<=“0011001010010010000000000000”:WHEN“01000011w,=>data_out<=H0011001011000011lLOOLOlOOlOO";WHEN”01000100”=>data_out<=”0011001001100111110010000010”；WHENH01000101n=>data-Oii^^OO11001001001001001001000000*';WHEN”01000110M=>dataout<=H0011001000001001001000011001WHENH010001HH=>dataout<=M0011001111100001001000000000H:——WHENH01001000n=>data_out<=,p0011001000000001100000100100";WHEN”01001001”=>data_out<=“0011001001000001100000000010”:WHEN"01010000M=>data_out<=H0010010100000010000001000000”;WHEN"'01010001n=>data_ont<=H0010010111100110000000010010M;WHEN”01010010M=>clataout<=H0010010010010011110011000000”;WHEN"01010011n=>data_out<=n0010010011000011110010010010";WHEN"01010100M=>data_out<=H0010010001100101001001000000";WHEN"'01010101n=>data_out<=n00100100010010010010000100101';WHEN-OlOlOll0M=>data_out<=n0010010000001001100001000000“；WHEN"01010111^Xlataout<=nOO100101111000011000000100101';WHEN?'OlOll000”=>datjoutv=”0010010000000000110011000000”;WHEN"01011001n=>data_out<=nOO10010001000000110010010010";WHEN”01100000”=>ddta_out<i0000010100000010000001000000”；WHENn0110000r*=>dataout<=H0000010111100110000000000010,r:WHENy01100010M=>data_out<=nOOOOO10010010011110010100100"：WHEN“01100011—>data_out<=nOOOOO10011000011110010000000*';WHEN”01100100H=>data_out<=H0000010001100101001000011001”；WHEN”01100101H=>data_out<=H0000010001001001100001000000";WHEN”01100110,,=>data_ont<=H0000010000001001100000000010";WHEN“01100111"=>dataout<=n0000010111100000110010100100”；WHEN“01101000,r=>data_out<=H0000010000000000110010000000”;WHENM0110100rr=>dataout<=H00000100010000001001000U001,1;WHEN,,01110000,,=>data_out<=,,1111000100000010000001000000,WHENH01110001n=>data_out<=，r1111000111100110000001111000“WHEN“01110010n=>data_out<=,r111100001001001111001001100WHEN“01110011n=>clata_out<=n1111000011000001001001111001nWHENu01110100n=>data_out<=H1111000001100101001000000000*WHEN“01110101n=>data_out<=n11110000010010011000000100101WHEN“01110110”=>dina_out<=”1111000000001000110010100100”WHEN"OlllOlir^dataout<=v1111000111100000110010010000"WHENH01111OOOn=>clata_out<=M1111000000000000100100000010fWHEN“01111001n=>clata_out<=M111100000100000000010011000O'WHEN”10000000M=>data_out<=H0000000100000010000001000000*WHEN”1000000l”=>data_outvi0000000111100110000000000000"WHENH10000010M=>data_out<=H0000000010010011110010000010”WHEN”10000011n=>data_out<=nOOOOOOOO11000001001000011001”WHEN”10000100”=>data_outv=“0000000001100101100000100100”WHEN”10000101”=>data_outv=”0000000001001000110011000000“WHEN”1000011