单片机上机操作考试题部分答案

1、1.使得8个发光二极管循环点亮，采用定时器方式0使得每个发光二极管点亮的时间为0.5s 。U1*卜 XTAL1P0.0/AP0PO 1/AD1 P0.2/AU2XTAL2PO3/AD3FQ.WAB4沔3&3718363534r U.OJMUOPO.B/AOBRSTP0.7/AD7P2.0/fieP2.iffieP2.2A1033e善22 2324IPSENP23/A11ALEP2 4ZA12EAP2,SW13P2 6gl4F2.7/A15P1.0P3.0/RXDP1.1P3,VTXD302531_2627281110211123P1.2P3.2/INT0P1.3P33/INT1P1.4

2、P3.4/T0P1.5P3 5/T1IP1,8P3.8WRP1.7P3,7；RD514G15716817ATSS C51v T EXT. R1- 220 GREEN . .text工 - R2 220,. M.GREEN .v-c, . . R3 .- 220 GREEN .R5，220 ， .-序"GREEN,wT至黑T*.R6 . Z2Q -MGREEN . . . kR7 -.UE加GREEN#include<reg51.h>#include<intrins.h>#define uchar unsigned char uchar T_count=0;/定

3、时中断void toProc() interrupt 1TH0=(8192-5000)/32; /恢复初值TL0=(8192-5000)%32;if(+T_count=100)/0.5s 移动一位P0=_crol_(P0,1);T_count=0;/主函数void main()(TMOD=0;TH0=(8192-5000)/32; /5ms 定时TL0=(8192-5000)%32;EA=1;ET0=1;TR0=1;P0=0xfe;while(1);2.完成下面电路所示的功能，K1, K2对应两个开关按键。P1 口对应发光二极管的状态P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1

4、.7K1=0,K2=0oooo°oooK1=0,K2=1°oooK1=1,K2=0ooooK1=1,K2=1U1-JEXl> aADIR2EENGREENK10 R E E NR6GREEN T>.KT 4，»- ©#include<reg51.h>POQfAJMXTAL1 =；PO.1/AJD1PO.2XAD2PO.3XAD3XTAL2PCL的。4P0.5/ADSPO.iS/ADBiP0.7/AD7RSTP2.1/WP2.2/A1DP2.a/A11PSEHP2.4/A12AL£P2.5/A13EAP2.S/A14P3.

5、Q/RXDF1.0P3.1/T&P1.1P3,MNTOPI 2P3.3/1NHF1.3P3.4/TDF1.4P3.fi/T1P1.6P15P3.7/RDP1.7ATe3C51GREEN#define uint unsigned int#define uchar unsigned char sbit k1=P3 A2;sbit k2=P3八3;uchar i;while(-x)for(i=0;i<120;i+);/ 主函数void main()while(1)if(k1=0)&&(k2=0)P1=0x00;delay(10);else if(k1=0)&&a

6、mp;(k2=1)P1=0xcc;delay(10);else if(k1=1)&&(k2=0)P1=0xf0;delay(10);elseP1=0xff;delay(10);/K1 、 K2 同时按下/K1 按下，K2不按/K2 按下， K1 不按3. 在一个数码管上循环显示“H“E “ LL “ O , 循环的时间为1s。/延时void delay(uint x)'3- H-a - R -U1 一 ai.上 ». a.ndXTAL1PO.CWAMP0JZAD1PDJ27Al)2XTAL2PCL3XAD3PO.4ZAD4FO 5MMiiriRSIP O 7&

7、#171;I>7P23陶-sP2AffiQ*u a»P2jWl6，.S3PSfNP 之 J/A11.ALErr=.EAP2.&rAi3P2.0jW.1i4P2.7JA15P1.0P3.O/RXDP1.1P3 l/TXDQ,1F1.2P3 ZyiHTOP1.3P3.3/1HT1_ _ _ _5P1.4ra.-VTO_ eP1.5P3.5/T1j _ _ _ _ZP1.6P3J3/WRgP1.7P3 J/RD.ATBQ.W.I<TEXT>：A：3938373635五3332ERP1 . RESFACKS - hTEXTb .，21221aBBn202728#in

8、clude<reg51.h>#define uchar unsigned char#define uint unsigned intuchar code tab=0xf6,0xf9,0xb8,0xb8,0xbf;uchar T_count=0;uchar i=1;void t0Proc() interrupt 1 TH0=0x3c;TL0=0xb0;if(+T_count=10) P0=tabi;i=(i+1)%5;T_count=0;)void main()TMOD=1;TH0=0x3c;TL0=0xb0;EA=1;TR0=1;ET0=1;P0=tab0; / 初始化 P0 口w

9、hile(1);4 .在6个数码管上分别显示自己学号的后六位数字。a4叩心 n N把卜上用kXTALIKT解URETFgQTAKl单口君兔g POADQ E*具口* FDS*AH 卡口科直蟠 FD.7MDK7fza/e rz.wwP73A1D PZAH IPZAG F7SfAt3 P2£A14 一1?慎格门口但”wde FajfflTTF3.«HD F3SmP3.W ，m_力TE#include<reg51.h>#include<intrins.h>#define uchar unsigned char#define uint unsigned in

10、tuchar code tab=;/ 学号自己设置uchar i； while(x-) for(i=0;i<100;i+); /主函数 void main() uchar k; uchar wei=0x01;P0=tab0;P2=0x01;delay(1000); while(1) for(k=1;k<6;k+) wei=wei<<1;P0=tabk; / 发送数字段码 P2=wei; /发送位码 delay(1000); 5 .做一个简易30s的倒计时秒表，秒表的显示通过8个发光二极管显示出来。WJIJjeQHiJ21网*>:一 112一旧#include<

11、;reg51.h>#define uchar unsigned charvoid delay1s() uchar i; for(i=0;i<10;i+)TH1=0x3c;TL1=0xb0;TR1=1;/ 启动 T1while(!TF1); 判断T1有无请求 TF1=0; void main() uchar i; uchar t;TMOD=0x10; 选择 T1 计时 while(1) for(i=30;i>0;i-) t=(i/10)<<4)|(i%10); 高四位显示十位，低四位显示个位P1=t;delay1s(); 6 .使用外中断0来控制，去实现下列功能。其

12、中K1为按键，P1 口对应8个发光二极管的状态P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7无按键按下（循环）OOOOOO有按键按 下OOOOA- DIRS .220 Z2BS£西7>LEPORE ENDBLEO-ORE EN,LED-GREEN03之iaid一于3 4 5 B- 77 -H i 4支 2 3 332mam POd/ADl PO.2MD2 PO.3IAD3 PCk*口 4POJ0WDO Pa.7WD7P2.(W用 P2.1i«W P2.2W10 P2.3W11 P24n也P2节除好 P2的伊也I P2.7/A15P5.ORXD pa.

13、inxp P3.2HMTD P3.3i«ilNT1 PS.Ta P3.5/T1 P3.B1WR P3.7i«RDX1AL1XTAL2PSENP1.0 F1.1 F12 Fl.3PI.4 P1.5 P1.8LE SCREENEJ?R2220220 LEDGREEM -.： -jLEGORE END5R4220 <TEXT>R53 口 豆 a220 <TEXT>RB220<r£XT>R"220 LBGREEN r：T£XT>D8#include<reg51.h>#define uint unsi

14、gned int#define uchar unsigned charuchar code tab=0xcc,0x30;sbit k1=P3A2;/延时void delay(uint x)uchar i;while(-x)for(i=0;i<120;i+);void int0Proc() interrupt 0P1=0xf0;/主函数void main()uchar j;EA=1;EX0=1;IE0=1;while(1)(if(k1=1) / 未按下(for(j=0;j<2;j+)(P1=tabj;delay(500);8 .采用定时器方式1使得8个发光二极管按如下方式点亮，循环的

15、时间为 2sP1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7°oooooooooooD1U115次 TQL1POjO/ADOP0.VAP1PD.2ZAD2XTAL2P0.3/AD3F0.4D4PD.5MD5 PO.0/AD6RSTP0.7/A&7P2,Qffl8P2.VAQ P2.2/A1Q363837,JS_的353433Q32,r-21-2222zgPSENF2.3/A11ALEF2.4/A12EAP2.5/A13P2.WA14P2.7/A15P1.0P3.0/RXDpuP3,irrxpP1*P3.2/INTO上胃iL2;272S110211312413P

16、1.3户3.3/INT彳P1.4P3.4/TOP1.5P3.5/T1PT.6P3.67WRP1.7P3.7/RD514,6工X168J1.AT80C51<TEXT> 度怎REEN的怎REEN220，,R2 . .220 耳TEK R3 .曲-GREEN可0少 .E , ， , si 220 1 r %GREEN ,mTE/T% > n * R6，“LEOREEN兜-GREEMLEAGREEN220 式TEXT> R4 一220 a -R5 . .R7 220 R0 .#include<reg51.h> #define uchar unsigned char#

17、define uint unsigned intuchar code tab=0x0f,0xf0,0xcc,0x00;uchar T_count=0;uchar i=1;void t0Proc() interrupt 1TH0=0x3c;TL0=0xb0;if(+T_count=20)P0=tabi;i=(i+1)%4;T_count=0;void main()TMOD=1;TH0=0x3c;TL0=0xb0;EA=1;TR0=1;ET0=1;P0=tab0; / 初始化 P0 口while(1);9 . 在一个数码管上循环显示“0”“ 1” “ 5” 3 个数字，循环的时间为1s。L, ,&

18、#39; LU1, 帕?XTALIPO.O/ADO39rr.r=P0.1/A01381UNUaKP0.2M&2“ 怡XTAL2P0J3WD336r-r-=，PO.4/AD436*ai.P0B/A05il4ilP0.6/ADfi33RSTF0.7/A&732J4hbgahP2.0/«21P2.i/e2223、 .PSEMP2.3/A1124AUEP2.A1225EAF2.*-A13加P2 B/A1427P2.7/A1523_LP10P3.C/RXI>10J 一 t 2P1.1P3.1/TD11,a B B .3P1 2P3 2/IMTO隹,乌P13P3.3/1NT

19、1I. . .P1.4P3.4/T014P1,5P2.5/T1J5 7P1.8P3.S/WRIo“，._8_P1.7P3.7/FD1,&T弱31 , . LTEXT#include<reg51.h>RP1RESPACK< TEXT>-，#define uchar unsigned char #define uint unsigned int uchar code tab尸0xbf,0x86,0xed;uchar T_count=0;uchar i=1;void intoProc() interrupt 1 TH0=0x3c;TL0=0xb0;if(+T_coun

20、t=10) P0=tabi;i=(i+1)%3;T_count=0;.RP1 .订日g.UIXT百图KT*星RHT>H10 1m3FFTflrEPAL£ 苣百PP FFFzjy>s大4fPH21Ht F73fA1lF7SAO FUAW PZT 陋 gP3IVHXD FJ ItfTTO 叮例型I 叮*DEF3STI pitHTFPDElfAH? FQAbl PDADZP山加X FDPAI* PIWAK PQ77APT15PJ-S、'帕m 一回 1 iz*4 .13P3JdZTl-void main()TMOD=1;TH0=0x3c;TL0=0xb0;EA=1;TR0

21、=1;ET0=1;P0=tab0; / 初始化 P0 口while(1);10 .在4个数码管上稳定显示出“ A"C”"E”"P'四个字符。安叩口3r叩工35PLi4 xpir+s JtFDS- 'TJFOTT#include<reg51.h> #define uchar unsigned char#define uint unsigned int void delay(uint x) uchar i;while(x-)for(i=0;i<100;i+);void main()while(1)P0=0xf7; /AP2=0xb9;

22、 /CP3=0xf9; /EP1=0xf3; /P delay(500);12.做一个20s的简易秒表，当按键 K1按下时，秒表暂停计数，K2按下时，开始计数。IJ1?XTAL1ro.OW.DOra 1/aoi P02M2XTAL2P0.3JA03RQ.4ZAID4 FC.5MD5 R0.6/AIDS RSIR0.7/A1DTP2.0/W F2.1/M P22M10PSHP2 3W11ALEP2.WI2EAP2qA13R2国阳4 P2.7M1SP1 JOP3.0/RXDP1.1P3.1/TX0P12P3,2ANTOPUF3.3/1NT1P1 4P3.4/T0P1.5P3.fi/T1F1.0PS

23、.GRP1.7P3.7/R&3Q POO103s pO.137 p0.22Ba35 pO-134 e0.533 p0 3.0292Hp222 醛.123P2 224pN 名25p2.4ii26p2-527P2J02811312413514a7怪917AT8flC5t#include<reg51.h> #define uint unsigned int#define uchar unsigned charuchar tab尸0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f);sbit k1=P3A2;sbit k2=P3A3;

24、uchar T_count=0;uchar i=0;void delay(int x)uchar i;while(x-)for(i=0;i<100;i+);void t0Proc() interrupt 1TH0=0x3c; / 恢复定时器0 初值TL0=0xb0;转换状态if(+T_count=10) /100ms*10=1s i+;P0=tabi/10;P2=tabi%10;if(i=20)i=0;T_count=0;void main()P0=tabi;P2=tabi;TMOD=0x01;TH0=0x3c;TL0=0xb0;while(1)if(k1=0 && k2

25、=1)EA=0;ET0=0;TR0=0; break;else if(k1=1 && k2=0) EA=1;ET0=1;TR0=1; break;14.使用外中断1来控制，当无按键按下时8个发光二极管循环点亮， 循环点亮的时间为1s,有按键按下时，8个发光二极管全部熄灭。38-73435.益一32232427XT ALUP0.1WD1F0.2iWiD2P0.2MDGXTAL2PO.404加加所电P0BJAD8P0.7iWD7RSTP之口加6P2.1Mp2之律mPN3依十1PSEHF2.4/A12ALEP2.BifA13EAPM 16 ml4P27A15P3.O/RXDP1.0P

26、1 1P3.2/1 NIUPI .2P3.3ANT1P1.3P3.4TTOP1.4P3.5mP1.5户3方而帚FibF3.7/RDP1.7U119ICg8<1.'3J45#include<reg51.h>#include<intrins.h>#define uchar unsigned char#define uint unsigned int sbit k1=P3A2;uchar code tab尸0x01,0x03,0x07,0x0f,0x1f,0x3f,0x7f,0xff);uchar T_count=0;uchar i=1;/T0 定时void T

27、0Proc() interrupt 1TH0=0x3c;TL0=0xb0;if(+T_count=10)P1=tabi;i=(i+1)%8;T_count=0;/INT1 中断函数void Int1Proc() interrupt 2 P1=0xff;EA=0;EX1=0;IT1=0;ET0=0;TR0=0;/ 主程序void main()TMOD=1;EA=1;ET0=1;TR0=1;TH0=0x3c;TL0=0xb0;EX1=1;IT1=1;P1=0xfe;while(1);P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7K1=0,K2=0K1=0,K2=1ooooK1=1

28、,K2=0oo 1ooooK1=1,K2=1oo°o16.完成下面电路所示的功能,K1, K2对应两个开关按键。P1 口对应发光二极管的状态U110五14伯izZPQ.tV同MxtalkPO.2/W2PO.3/AU3XTAL2F0.-WAD4PO.5/AJO5PO.B/ADBPO.7/AD7RSTP2.0XfflP2.1i/AaP2.2/A10P2.3ZA11PSENP2.4/A12ALEP2.5XA.13EAP2.a/W4P27/A15曜Q恤3P1 0P3.1/T冲P1.1P3.2/1M1DPU2R3J 加 T1P1 3ra.q/njF1.<lP3.fi/T1P1 5瓯P1

29、6F3.7/RDF1.7a&.AI&9C512930 五DIgBLUEWBLllE事®UE四日LJEES9aLUE .gp-BLUE研HWE.LE&-BLUE.TEXT" 220 TEXT> a R2.- 220:出- 220 或 TWIT为. R4> 220 > . <r£r>. R5 -.T 卜220 贰TE其人 R6 一'220 1 1 . mTEMTa . R7.T 4 220 . <TfAT.RB .220 MT6m#include<reg51.h>#define uint

30、unsigned int#define uchar unsigned charsbit k1=P3A2;sbit k2=P3A3;/延时void delay(uint x)(uchar i;while(-x)(for(i=0;i<120;i+);)/主函数void main()while(1) if(k1=1)&&(k2=1)都未按下0:未按下，1:按下P1=0x00;delay(10); else if(k1=1)&&(k2=0) /k2 按下，k1 未按下P1=0xf0;delay(10); else if(k1=0)&&(k2=1)

31、/k1 按下，k2 未按下P1=0xcf;delay(10);else if(k1=0)&&(k2=0)/ 都按下P1=0x55;delay(10);1显示的时间为1s,状态217.完成下面电路的功能，P1 口对应发光二极管的状态，状态显示的时间为2s,状态3显示的时间为3s,如此循环P1.0P1.1P1.2状态1状态2O状态3O3B3523P0.0/AD0XTAL1 <P0.1/AD1P0.2/A02P0J/AD3XTAL2P0.*VA04P0.5/A05P0.6/A0GP0.7/ADJ7ASTP2.1/P2.2/A10P2.3/A11PSENP24A12ALEP2.5

32、/A13EAP2.6/A14P2.7/A15P3.0/RXDP1jOP3.1/TXDF1.1P3.2/INT0F1J2P3.3/INT1P1.3P3.中 TOF1.4P3.5/T1F1.5F3.6/WRP1.6F3.7/RDF1.715 .18_2537393819 ' I r r r r1S q2Q30U.tJ(TEXTSB 7 s - o 12 2 2 1 1D131LEERED s7EXT>.R1- 1220« TEXT需LED-REO TEXT匕£TE/T>D3LED-REDR3 :H I220 , , < T E ' '&

33、#39; "-#include<reg51.h>#define uchar unsigned char#define uint unsigned intuchar code tab尸0x05,0x06,0x03;uchar T_count=0;uchar State=0;uchar i=1;void t0Proc() interrupt 1 TH0=0x3c;TL0=0xb0;switch(State)case 0:if(+T_count=10) P1=tabi;i=(i+1)%3;T_count=0;State=1;break;case 1:if(+T_count=20

34、)P1=tabi;i=(i+1)%3;T_count=0;State=2;break;case 2:if(+T_count=30)P1=tabi;i=(i+1)%3;i=1;T_count=0;State=0;break;void main()TMOD=1;TH0=0x3c;TL0=0xb0;EA=1;ET0=1;TR0=1;P1=tab0;while(1);18.彩灯系统，实现8个发光二极管从左到右点亮，每个发光二极管点亮的时间为2s,然后从右到左亮，每个发光二极管点亮的时间为1.5s.X7AL1X7AL2MfPO WPO PO 1WD1 rowpz PD州心3 PO4AM FO-gJ ro

35、wjw gm阜mPijoweF7TJ 厢 Emp fr54«A” F2.4SA12 F2.SW13 frSimw MJ/AtiF3.OJRXP 1HXPPS 2ifwTa P3.34NT1P3H1D P3.WT1F2 3Ht P3.7/FCAT8&C31 «TEXT*_#include<reg51.h>#include<intrins.h>#define uchar unsigned charuchar code tab尸0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80;uchar code tab1=0x80,

36、0x40,0x20,0x10,0x08,0x04,0x02,0x01;uchar State=0;uchar T_count=0;uchar i=1;void t0Proc() interrupt 1 TH0=0x3c;TL0=0xb0;switch(State)case 0:if(+T_count=20) P2=tabi;i=(i+1)%8;if(i=7) State=1;T_count=0; break;case 1:if(+T count=15)i=(i+1)%8;P2=tab1i;if(i=7) State=0;i=1;T_count=0; break;void main()TMOD=

37、1;TH0=0x3c;TL0=0xb0;EA=1;ET0=1;TR0=1;P2=tab0; while(1);19.在4个数码管上显示出当天的日期。raJVADD ra.-VAM国-g EWX pg5内修 rasAts hdj/a 由F2MF工力具11 Pza'Aii FZ.aIZ F7SA13 F3RH F2n限售F3I3fK4 pj.vr pnwmn f33TITT”STI 131 ”而#include<reg51.h>#define uchar unsigned char#define uint unsigned intuchar code tab=0x06,0x5b

38、,0x06,0x6f;void delay(int x)uchar i;while(x-)for(i=0;i<120;i+);)void main() P0=tab0;P2=tab1;P3=tab2;P1=tab3; delay(500);)20.完成下面电路的功能，P1 口对应发光二极管的状态，状态1显示的时间为3s,状态2显示的时间为1s,状态3显示的时间为0.5s ,状态4显示的时间为0.1s ,如此循环P1.0P1.1P1.2P1.3状态1OO状态2O状态3状态4OOO°U139P0.0/ADOXTAL1P0.1/A01P0.2/AD2P0.3/AD3XTAL2叩.卬足

39、。4P0.5/AD5PO.B/ADeP0.7/AD7RSTP2.0/CP2.1NP2.2/A1O伯3SA33_133332921222324P2.3/A11PSENP2A12处里2530203127r-t -OJrM. 1EMP2.B/A14P2 7/A15P3,0/RXDP1 0P3.VTXDP1.1P3 2/INTOP1.2P3.3/iNTTP1 3P34ToP1.4口。昌?T*"!04 Ka 281011212313<414T-1561Br J-DJ11r 1 .OP3.6/WRP1.6P37/RDP1.77178AT80IC51 < TEXT>D1R122G

40、LED-GREEN . - TE.,LEDGREEN. R2 .i 220. tTEXT>,LED-GREEN .TEXT>. D4 , “ ,LEDHREEN. FEXT>.R3220 T EXT>R4220 < T EXTmA：#include<reg51.h> #define uchar unsigned char#define uint unsigned intuchar code tab尸0x0c,0x0e,0x0f,0x00;uchar T_count=0;uchar State=0;uchar i=1;void t0Proc() inte

41、rrupt 1 TH0=0x3c;TL0=0xb0;switch(State)case 0:if(+T_count=30) P1=tabi;i=(i+1)%4;T_count=0;State=1;)break;case 1:if(+T_count=10) (P1=tabi;i=(i+1)%4;T_count=0;State=2;)break;case 2:if(+T_count=5)(P1=tabi;i=(i+1)%4;T_count=0;State=3;)break;case 3:if(+T_count=1)(P1=tabi;i=(i+1)%4;T_count=0;State=0;)brea

42、k;void main()(TMOD=1;TH0=0x3c;TL0=0xb0;EA=1;ET0=1;TR0=1;P1=tab0;while(1);23.数码管数字显示控制程序设计。 控制要求：用按键K1和K2分别控制数码管显示数字 09 的顺序，当按下K1键时按从。到9的顺序显示，当按下K2时按从9到0的顺序显示。时间间隔 均为1秒。硬件电路如图所示。FE W心- 印修“； rn .jaw f w*= =3.'<£ 即fr万T.L.JI.2 a由皮城-y阳e"J 'a,二:7"必救4 飞"可T XK-LM个PR 一疝广 呼二词&qu

43、ot;mmami-£="1-i*xh#include<reg51.h>#define uchar unsigned char#define uint unsigned intuchar code tab1=0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f;uchar code tab2=0x6f,0x7f,0x07,0x7d,0x6d,0x66,0x4f,0x5b,0x06,0x3f;uchar T_count=0;sbit k1=P1A0;sbit k2=P1Al；uchar i=0;void t0Proc()

44、 interrupt 1TH0=0x3c;TL0=0xb0;if(+T_count=10)T_count=0;i=(i+1)%10;)void main()TMOD=1;TH0=0x3c;TL0=0xb0;EA=1;ET0=1;TR0=1;P0=0x3f;while(1)if(k1=0 && k2=1)P0=tab1i;else if(k1=1 && k2=0)P0=tab2i;24. 89C51与PC通过串口通信，单片机采用方式 3串行通信，晶振都采用 12MHz波特率为 1200Baud。要求：当单片机收到 PC发来的数据“ S”后，将30H-3FH的16个

45、字节发送给乙 机，当单片机收到“ P” H时就发40H-5FH的32个字节数据。#include<reg51.h>#include<stdio.h>char *startPoint;char *endPoint;void sendData() (if(startPoint <= endPoint) ( SBUF=*startPoint; +startPoint; void startSend(char *start ,char *end)(startPoint=start;endPoint = end;sendData();void serialPorc() interrupt 4if(TI)TI=0;sendData();elseRI=0;if(0x53=SBUF)startSend(0x30,0x3f);else if(0x50=SBUF)startSend(0x40,0x5f);void main()TMOD=0x20;TH1=0xe6;TL