專題七動(dòng)態(tài)掃描電路設(shè)計(jì)

專題七：七段顯示器動(dòng)態(tài)掃描電路設(shè)計(jì)

一、教學(xué)內(nèi)容：七段顯示器動(dòng)態(tài)掃描電路設(shè)計(jì)二、教學(xué)目的及要求：1、駕馭VHDL語(yǔ)言的基本結(jié)構(gòu)及編程思想。2、駕馭七段顯示器動(dòng)態(tài)掃描電路設(shè)計(jì)方法。三、授課課時(shí)：6課時(shí)

設(shè)計(jì)要求：1、設(shè)計(jì)一個(gè)七段數(shù)碼管動(dòng)態(tài)掃描電路。數(shù)碼管個(gè)數(shù)為8個(gè)，共陰極接法。2、設(shè)計(jì)一電路，限制上述電路實(shí)現(xiàn)“12345678”八個(gè)數(shù)字的顯示，要求顯示方式為：（1）自左至右逐個(gè)點(diǎn)亮數(shù)碼管，最終全亮；再重復(fù)以上動(dòng)作，每次變更時(shí)間間隔為1秒。（2）自左至右點(diǎn)亮數(shù)碼管，每次只點(diǎn)亮一個(gè)，最終全息滅，再重復(fù)以上動(dòng)作，每次變更時(shí)間間隔為1秒。（3）先中間兩個(gè)點(diǎn)亮，再依次向外點(diǎn)亮；全亮后，再依次向中間熄滅；重復(fù)上述步驟，每次變更時(shí)間間隔為1秒。相當(dāng)于實(shí)現(xiàn)8279的顯示部分的功能一、七段顯示器動(dòng)態(tài)掃描電路設(shè)計(jì)框圖abcdefgc6c5c1c4c2c3c7c8掃描控制器顯示字符碼存儲(chǔ)器循環(huán)取數(shù)電路同步時(shí)鐘發(fā)生器CLKA0A1A2地址線WR數(shù)據(jù)寫(xiě)入控制數(shù)據(jù)線RD讀A00A01A02數(shù)據(jù)線clk1clk2雙口RAM二、存儲(chǔ)器設(shè)計(jì)（8位8字節(jié)靜態(tài)隨機(jī)存儲(chǔ)器SRAM）LIBRARYieee;USEieee.std_logic_1164.all;ENTITYMEMO_RD_WRISPORT(WR,RD:INSTD_LOGIC;A:INSTD_LOGIC_VECTOR(2DOWNTO0);B:INSTD_LOGIC_VECTOR(2DOWNTO0);D:INSTD_LOGIC_VECTOR(7DOWNTO0);Q:OUTSTD_LOGIC_VECTOR(7DOWNTO0));ENDMEMO_RD_WR;顯示字符碼存儲(chǔ)器（8字節(jié)）A0A1A2地址線WR數(shù)據(jù)寫(xiě)入控制數(shù)據(jù)線D[7..0]Q[7..0]RD讀數(shù)據(jù)控制A00A01A02雙口RAMABARCHITECTUREaOFMEMO_RD_WRISSIGNALQ0,Q1,Q2,Q3:STD_LOGIC_VECTOR(7DOWNTO0);SIGNALQ4,Q5,Q6,Q7:STD_LOGIC_VECTOR(7DOWNTO0);BEGINPROCESS(WR,A)BEGINIFWR='1'THENCASEAISWHEN"000"=>Q0<=D;WHEN"001"=>Q1<=D;WHEN"010"=>Q2<=D;WHEN"011"=>Q3<=D;WHEN"100"=>Q4<=D;WHEN"101"=>Q5<=D;WHEN"110"=>Q6<=D;WHEN"111"=>Q7<=D;WHENOTHERS=>NULL;

ENDCASE;ENDIF;ENDPROCESS;PROCESS(RD,B)BEGIN

IFRD='1'THENCASEBISWHEN"000"=>Q<=Q0;WHEN"001"=>Q<=Q1;WHEN"010"=>Q<=Q2;WHEN"011"=>Q<=Q3;WHEN"100"=>Q<=Q4;WHEN"101"=>Q<=Q5;WHEN"110"=>Q<=Q6;WHEN"111"=>Q<=Q7;WHENOTHERS=>NULL;ENDCASE;

ENDIF;ENDPROCESS;ENDa;仿真結(jié)果：三、同步時(shí)鐘CLK頻率計(jì)算同步時(shí)鐘發(fā)生器CLKclk1CLK頻率計(jì)算：依據(jù)人的視覺(jué)暫留現(xiàn)象，一個(gè)數(shù)碼管所要顯示的字符只要在一秒內(nèi)點(diǎn)亮24次以上，則感覺(jué)上該數(shù)碼管沒(méi)有熄滅一樣。若8只數(shù)碼管要出現(xiàn)這種效果，要求在一秒內(nèi)每只數(shù)碼管要閃亮24次以上。則CLK頻率應(yīng)為24X8＝192Hz以上，為了削減閃爍現(xiàn)象，達(dá)到較好的顯示效果，取CLK頻率為1024Hz，每秒內(nèi)每個(gè)數(shù)碼管顯示次數(shù)為128次。CLK1=CLK;CLK2=CLK;四、循環(huán)取數(shù)電路設(shè)計(jì)LIBRARYieee;USEieee.std_logic_1164.all;ENTITYGET_CODEISPORT(CLK1:INSTD_LOGIC;D:INSTD_LOGIC_VECTOR(7DOWNTO0);

RD:OUTSTD_LOGIC;A:OUTSTD_LOGIC_VECTOR(2DOWNTO0);DOUT:OUTSTD_LOGIC_VECTOR(7DOWNTO0));ENDGET_CODE;該電路利用地址線A00、A01、A02對(duì)存儲(chǔ)器循環(huán)取數(shù)，并通過(guò)DOUT[7..0]送數(shù)碼管顯示。每個(gè)CLK1時(shí)鐘取出一個(gè)顯示碼并立刻送數(shù)碼管顯示。abcdefgRD讀A00A01A02數(shù)據(jù)線clk1循環(huán)取數(shù)電路D0—D7DOUT[6..0]DOUT1DOUT0DOUT2DOUT3DOUT4DOUT5DOUT6RDA地址信號(hào)發(fā)生電路鎖存信號(hào)產(chǎn)生電路讀信號(hào)產(chǎn)生電路A00A01A02RDCLK1鎖存器DOUT[6..0]D[7..0]鎖存信號(hào)LOAD循環(huán)取數(shù)電路內(nèi)部功能圖CLK1的上升沿鎖存ARCHITECTUREaOFGET_CODEISSIGNAL LOAD:STD_LOGIC;SIGNALQQ:STD_LOGIC_VECTOR(7DOWNTO0);SIGNALNUM:INTEGERRANGE7DOWNTO0;BEGINRD<=‘1’;LOAD<=CLK1;PROCESS(CLK1)BEGINIFCLK1'EVENTANDCLK1='1'THENNUM<=NUM+1;ENDIF;ENDPROCESS;

PROCESS(NUM)BEGINCASENUMISWHEN0=>A<="000";WHEN1=>A<="001";WHEN2=>A<="010";WHEN3=>A<="011";WHEN4=>A<="100";WHEN5=>A<="101";WHEN6=>A<="110";WHEN7=>A<="111";WHENOTHERS=>NULL;ENDCASE;ENDPROCESS;PROCESS(LOAD)BEGINIFLOAD‘EVENTANDLOAD=‘1’THEN-------上升沿鎖存

QQ<=D;ENDIF;ENDPROCESS;DOUT(7DOWNTO0)<=QQ(7DOWNTO0);ENDa;五、掃描限制器設(shè)計(jì)abcdefgc6c5c1c4c2c3c7c8掃描控制器clk2LIBRARYieee;USEieee.std_logic_1164.all;ENTITYSCAN_8ISPORT(CLK2:INSTD_LOGIC;C:OUTSTD_LOGIC_VECTOR(7DOWNTO0));ENDSCAN_8;掃描限制器時(shí)序圖ARCHITECTUREaOFSCAN_8ISSIGNALNUM:INTEGERRANGE7DOWNTO0;BEGINPROCESS(CLK2)BEGINIFCLK2'EVENTANDCLK2=‘1'THENIFNUM<=7THENNUM<=NUM+1;ELSENUM<=0;ENDIF;ENDIF;ENDPROCESS;Process(num)beginCASENUMIS

WHEN1=>C<="11111110";WHEN2=>C<="11111101";WHEN3=>C<="11111011";WHEN4=>C<="11110111";WHEN5=>C<="11101111";WHEN6=>C<="11011111";WHEN7=>C<="10111111";WHEN0=>C<="01111111";WHENOTHERS=>NULL;ENDCASE;ENDPROCESS;ENDA;地址數(shù)據(jù)線掃描限制器電路圖存儲(chǔ)器電路讀顯示碼電路列掃描電路應(yīng)用實(shí)例一：顯示“01234567”八個(gè)數(shù)字LIBRARYieee;USEieee.std_logic_1164.all;ENTITYdisp_dataISPORT(CLK:INSTD_LOGIC;WR:OUTSTD_LOGIC;A:OUTSTD_LOGIC_VECTOR(2DOWNTO0);Q:OUTSTD_LOGIC_VECTOR(7DOWNTO0));ENDdisp_data;ARCHITECTUREaOFdisp_dataIS--SIGNALQQ:STD_LOGIC_VECTOR(7DOWNTO0);SIGNALNUM:INTEGERRANGE7DOWNTO0;BEGINWR<=‘1’;PROCESS(CLK)BEGINIFCLK'EVENTANDCLK='1'THENIFNUM<=7THENNUM<=NUM+1;ELSENUM<=0;ENDIF;ENDIF;ENDPROCESS;PROCESS(NUM)BEGINCASENUMISWHEN0=>Q<="00111111";A<="000";WHEN1=>Q<="00000110";A<="001";WHEN2=>Q<="01011011";A<="010";WHEN3=>Q<="01001111";A<="011";WHEN4=>Q<="01100110";A<="100";WHEN5=>Q<="01101101";A<="101";WHEN6=>Q<="01111101";A<="110";WHEN7=>Q<="01111111";A<="111";WHENOTHERS=>NULL;ENDCASE;ENDPROCESS;ENDa;應(yīng)用實(shí)例二：數(shù)字增加依次重復(fù)顯示“12345678”八個(gè)數(shù)字應(yīng)用實(shí)例三：?jiǎn)螖?shù)字依次重復(fù)顯示“12345678”八個(gè)數(shù)字七段顯示器動(dòng)態(tài)掃描電路設(shè)計(jì)框圖abcdefgc6c5c1c4c2c3c7c8掃描控制器顯示字符碼存儲(chǔ)器循環(huán)取數(shù)電路同步時(shí)鐘發(fā)生器CLKA0A1A2地址線WR數(shù)據(jù)寫(xiě)入控制數(shù)據(jù)線RD讀A00A01A02數(shù)據(jù)線clk1clk2LIBRARYieee;USEieee.std_logic_1164.all;ENTITYdisp_data2ISPORT(clk,clk1s:INSTD_LOGIC;WR:OUTSTD_LOGIC;A:OUTSTD_LOGIC_VECTOR(2DOWNTO0);Qout:OUTSTD_LOGIC_VECTOR(7DOWNTO0));ENDdisp_data2;ARCHITECTUREaOFdisp_data2ISSIGNALNUM1:INTEGERRANGE7DOWNTO0;SIGNALnum2:INTEGERRANGE8DOWNTO0;SIGNALq0,q1,q2,q3,q4,q5,q6,q7:STD_LOGIC_VECTOR(7DOWNTO0);BEGINWR<='1';process(clk)beginifclk'eventandclk='1'thenifnum1<=7thennum1<=num1+1;elsenum1<=0;endif;endif;endprocess;

process(num1)beginCASENUM1ISWHEN0=>A<="000";qout<=q0;WHEN1=>A<="001";qout<=q1;WHEN2=>A<="010";qout<=q2;WHEN3=>A<="011";qout<=q3;WHEN4=>A<="100";qout<=q4;WHEN5=>A<="101";qout<=q5;WHEN6=>A<="110";qout<=q6;WHEN7=>A<="111";qout<=q7;WHENOTHERS=>NULL;endcase;endprocess;

process(clk1s)beginifclk1s'eventandclk1s='1'thenifnum2<8thennum2<=num2+1;elsenum2<=0;endif;endif;endprocess;process(num2)begincasenum2iswhen0=>q0<="00000000";q1<="00000000";q2<="00000000";q3<="00000000";q4<="00000000";q5<="00000000";q6<="00000000";q7<="00000000";when1=>q0<="00000110";q1<="00000000";q2<="00000000";q3<="00000000";q4<="00000000";q5<="00000000";q6<="00000000";q7<="00000000";when2=>q0<="00000110";q1<="01011011";q2<="00000000";q3<="00000000";q4<="00000000";q5<="00000000";q6<="00000000";q7<="00000000";

when3=>q0<="00000110";q1<="01011011";q2<="01001111";q3<="00000000";q4<="00000000";q5<="00000000";q6<="00000000";q7<="00000000";when4=>q0<="00000110";q1<="01011011";q2<="01001111";q