LCD 原理及驱动方法简介1、LCD 显示器原理LCD 是一种被动式显示器，其本身不发光，只是调节光的亮度。
LCD 利用液晶的扭曲－向列效应制成，这是一种电场效应，夹在两片导电玻璃电极间的液晶经过一定的处理，它内部的分子呈90°的扭曲，当线性偏振光透过时其偏振面便会旋转90。
当在玻璃电极上加上电压后，在电场作用上，液晶的扭曲结构消失，其旋光作用也消失，偏振光便可直接通过。
当去掉电场后，液晶分子又恢复其扭曲结构。
把这样的液晶置于两偏振片之间，改变偏振相对位置就可得到字的显示形式。
LCD 七段显示器有a~g 七段外，还有一个公共极COM 。
可用静态方式驱动，也可用动态方式驱动。
前者加直流信号，后者加交流信号。
今天所讲的LCD 驱动也是用动态方式驱动的。
当加在a~g 七段中的某一电极的方波与公共电极COM 上的方波信号同相时，相对电压为0，则该段不显示；当加在某段电极上的方波与公共电极COM 的非选通点上加只有选通点电压的少交叉效应的影响，这就是上面仅仅是COM口的驱动波形，那么SEG口的驱动波形又是怎样的呢？对应上面的6个时段，在COM口为高电平时，如果该段需要显示，则对应的SEG口输出低电平；反之，则输出高电平。
根据同LED的有关段显示的规则，得出如下表所示的段码表。
段码表：L C D码表(4位半-18.8.8.8）com1 seg1com2seg2c o m3s e g3com1seg4com2seg5c o m3s e g6digit f a b e g c dp d s f a b e g c d dp s 0000010101111101100 1110110111001001000 2100001101011110100 3100100101011011100 40101001111010110005001100101110011100 6001000101110111100 7100110111011001000 8000000101111111100 9000100101111011100a000000111111111000b011000101100111100c001011101110110100d110000101001111100e111111111000000000不显示f111101111000010000显示“-”3、程式流程图如下图所示：4、程式如下1;title:通用I/O口驱动LCD范例程式2;MCU:EM78P447BS,clock:2,crystal:4MHz3;LCD规格：1/2Bias,1/3duty4;writer:RenBin5;date:2005-5-2311:276;*****************************************************************7;程式说明：本程式是用通用I/O口驱动LCD的程式，用一个I/O口作COM口及SEG口8;9;-------------------10;port611;port64com112;port65com213;port66com314;port515;port504b/4c16;port514a/4g/4d17;port524f/4e/dp318;port543b/3c/s219;port553a/3g/3d20;port563f/3e/dp221;port722;port702b/2c/s123;port712a/2g/2d24;port722f/2e/dp125;port741b/1c/1h26;port751a/1g/1d27;port761f/1e28;---------------------------------29include<em78p447.inc>1C;*****************************************************;2C;Tilte:EM78447include file;3C;Description:The Definition of EM78x447Registers;4C;Company:ELAN MICROELECTRONICS(SZ)LTD.;5C;Author:YouFang.Bao;6C;Date:5/14/2004;7C;Version:v1.0;8C;******************************************************;9C;10C;======================================================;11C;Operational Registers Define;12C;======================================================;13C;14C;======================================================;15C;Registers R0~R3F;16C;======================================================;17C;18C;R0/IAR:Indirect Address Register19C;200000C R0==0x00210000C IAR==0x0022C;23C;R1/TCC:Time Clock/Counter24C;250001C R1==0x01260001C TCC==0x01270001C RTCC==0x0128C;29C;R2/PC:Program Counter&Stack30C;310002C R2==0x02320002C PC==0x0233C;34C;R3/PSR:Process Status Register35C;360003C R3==0x03370003C PSR==0x03380003C STATUS==0x0339C;{400007C GP==0x07;General read/write bit410006C PS1==0x06;420005C PS0==0x05;(PS0~PS1):Page Select Bits43C;----------------------------------------;44C;PS1PS0Program memory page [Address];45C;00Page0[000-3FF];46C;01Page1[400-7FF];47C;10Page2[800-BFF];48C;11Page3[C00-FFF];49C;----------------------------------------;500004C T==0x04;Time-out bit510003C P==0x03;Power down bit520002C Z==0x02;Zero flag530001C DC==0x01;Auxiliary carry flag540000C C==0x00;Carry flag550000C cy==056C;57C;R4/RSR:RAM Select Register58C;590004C R4==0x04600004C RSR==0x0461C;{620007C RS1==0x07;RAM-Bank Select Bit1630006C RS0==0x06;RAM-Bank Select Bit064C;65C;R5~R7:I/O Port Address66C;670005C PORT5==0x05680006C PORT6==0x06690007C PORT7==0x0770C;710005C P5==0x05720006C P6==0x06730007C P7==0x0774C;750005C R5==0x05760006C R6==0x06770007C R7==0x0778C;79C;R3F/ISR:Interrupt Status Register80C;81003F C R3F==0x3F82003F C ISR==0x3F83C;{840003C EXIF==0x03;External interrupt flag850000C TCIF==0x00;TCC overflow interrupt flag86C870008C mEXIF==0x08;External interrupt flag880001C mTCIF==0x01;TCC overflow interupt flag89C;}90C;91C;92C;======================================================; 93C;Special Purpose Registers Define;94C;======================================================;95C;96C;IOC5~IOC7:I/O Port Control Register97C;980005C IOC5==0x05;Bit[n]=1,Set P5[n]as input pin,n=0~7 99C;Bit[n]=0,Set P5[n]as output pin, n=0~7100C;1010006C IOC6==0x06;Bit[n]=1,Set P6[n]as input pin, n=0~7102C;Bit[n]=0,Set P6[n]as output pin, n=0~7103C;1040007C IOC7==0x07;Bit[n]=1,Set P7[n]as input pin, n=0~7105C;Bit[n]=0,Set P7[n]as output pin, n=0~7106C;107C;108C;IOCB/WCR:Wake-up Control Register for PORT6109C;110000B C IOCB==0x0B111000B C WCR==0x0B112C;{1130007C WUE7==0x07;Control bit is used to enable the wake-up function of P67pin1140006C WUE6==0x06;Control bit is used to enable the wake-up function of P66pin1150005C WUE5==0x05;Control bit is used to enable the wake-up function of P65pin1160004C WUE4==0x04;Control bit is used to enable the wake-up function of P64pin1170003C WUE3==0x03;Control bit is used to enable the wake-up function of P63pin1180002C WUE2==0x02;Control bit is used to enable the wake-up function of P62pin1190001C WUE1==0x01;Control bit is used to enable the wake-up function of P61pin1200000C WUE0==0x00;Control bit is used to enable the wake-up function of P60pin121C;0:Enable internal wake-up122C;1:Disable internal wake-up123C;124C;IOCE/WDTCON:WDT Control Register125C;126000E C IOCE==0x0E127000E C WDTCON==0x0E128C;129C;IOCF/IMR:Interrupt Mask Register130C;131000F C IOCF==0x0F132000F C IMR==0x0F133C;{1340008C mEXIE==0x08;EXIF Interrupt enable bit135C;0:Disable EXIF interrupt136C;1:Enable EXIF interrupt 1370001C mTCIE==0x01;TCIF Interrupt enable bit138C;0:Disable TCC interrupt139C;1:Enable TCC interrupt140C;141C;======================================================; 142C;Others Define;143C;======================================================; 144C;145C;Bit set use BC or BS146C;1470000C B0==0x001480001C B1==0x011490002C B2==0x021500003C B3==0x031510004C B4==0x041520005C B5==0x051530006C B6==0x061540007C B7==0x07155C;======================================================; 156C;Macros Define;157C;======================================================; 158C;----------------------------159C;160C Page0MACRO161C;162C BC PSR,PS0163C BC PSR,PS1164C;165C ENDM166C;167C;----------------------------168C;169C Page1MACRO170C;171C BS PSR,PS0 172C BC PSR,PS1 173C;174C ENDM175C;176C;----------------------------177C;178C Page2MACRO179C;180C BC PSR,PS0 181C BS PSR,PS1 182C;183C ENDM184C;185C;----------------------------186C;187C Page3MACRO188C;189C BS PSR,PS0 190C BS PSR,PS1 191C;192C ENDM193C;194C;----------------------------195C;196C Bank0MACRO197C;198C BC RSR,RS0 199C BC RSR,RS1 200C;201C ENDM202C;203C;----------------------------204C;205C Bank1MACRO206C;207C BS RSR,RS0208C BC RSR,RS1209C;210C ENDM211C;212C;----------------------------213C;214C Bank2MACRO215C;216C BC RSR,RS0217C BS RSR,RS1218C;219C ENDM220C;221C;----------------------------222C;223C Bank3MACRO224C;225C BS RSR,RS0226C BS RSR,RS1227C;228C ENDM229C;----------------------------230C;231C;************************************************; 232C;Clear EM78P447General Register Macro Program; 233C;; 234C;************************************************; 235C;236C m447clrrambank macro237C;238C mov a,@0x10239C mov rsr,a240C$_Clrloop:241C clr r0242C inc rsr243C jbc rsr,6244C bs rsr,5245C jbc rsr,7246C bs rsr,5247C jbs status,z248C jmp$_clrloop249C endm30include"e:\lcd\lcddriverram.inc"1C;title:lcddriver register define2C;mcu:em78p447sb3C;---------------------------------------4C;50010C reg_acc1==0x1060011C reg_acc2==0x1170012C reg_acc3==0x1280017C temp_value==0x17;温度寄存器90019C humi_value==0x19;湿度寄存器10001B C sysstatus==0x1b;标志寄存器11C;--------------------------------------12C;bank1130020C mstimer==0x20140021C stimerlow==0x21150022C stimerhigh==0x22160023C cont==0x2317C;180024C commondata==0x24;common数据寄存器190025C segdata==0x25;segment数据寄存器20C;210026C temp1==0x26;中间变量寄存器220027C temp2==0x27;中间变量寄存器230028C temp3==0x28;中间变量寄存器240029C temp4==0x2925C;26002A C tempL==0x2a;温度bcd码低位寄存器27002B C tempH==0x2b;高位28002C C humiL==0x2c;湿度bcd低位码寄存器29002D C humih==0x2d;高位30C;31002E C timer05s==0x2e;0.5s寄存器32C;temp_value==0x2f;分钟寄存器33C;humi_value==0x30;小时寄存器34C;---------------------------------------------35C;register bit define36C;sysstatus register define370003C timer500ms==3;500ms标志380004C LCDdsp==4;LCD显示标志390005C datachange==5;数据更新标志400006C timer==6;定时标志410007C am==7;上下午标志42C;常数定义4300B2C tcc_5ms==178;tcc5ms timer4400C8C kmstimer==200;1000ms timer45000C C segment==12;define LCD segment data 460002C duty==2470003C common==3;2;define LCD common data 480002C bias==231;32org0xfff3300FFF0000nop34org035000001408jmp start36org137000010000nop3800002083F bc r3f,tcif39000030B1B bs sysstatus,lcddsp40000040B9B bs sysstatus,timer41000051886mov a,@(256-122)42000060041mov tcc,a43000070013reti4400008start:45M m447clrrambank;清寄存器0000818101MOV A,@(16)0000900441MOV RSR,A0000A1??0001$_CLRLOOP:0000A00C01CLR R0,0000B05441INC RSR,0000C0D841JBC RSR,60000D0B441BS RSR,50000E0DC41JBC RSR,70000F0B441BS RSR,5000100E831JBS STATUS,Z00011140A1JMP??0001$_CLRLOOP,46000121800mov a,@0x047000130045mov port5,a48000141800mov a,@0x049000150005iow ioc550;51000161800mov a,@0x052000170046mov p6,a53000181800mov a,@0x054000190006iow ioc655;560001A1800mov a,@0x0570001B0047mov p7,a580001C1800mov a,@0x0590001D0007iow ioc760;610001E1804mov a,@0b00000100;TCC=1:32,4.096ms 620001F0002contw63000201811mov a,@0x116400021000E iow ioce65000221801mov a,@0x016600023000F iow iocf67000241886mov a,@(256-122)68000250041mov tcc,a69;7000026183F mov a,@63;12;59;11;88;00;88;2371000270057mov temp_value,a7200028184A mov a,@74;34;11;11;88;00;88;30 73000290059mov humi_value,a;74;750002A1806mov a,@(common*2)760002B0064mov commondata,a770002C0010eni78;****************************************7980;****************************************810002D main:820002D0004wdtc830002E1096call lcddisplay840002F142D jmp main85;**************************************** 8600030LCD1_table:;段码表87000300020TBL88000311C00RETL@0B00000000;089000321C06RETL@0B00000110;190000331C04RETL@0B00000100;2 91000341C04RETL@0B00000100;3 92000351C02RETL@0B00000010;4 93000361C01RETL@0B00000001;5 94000371C01RETL@0B00000001;6 95000381C04RETL@0B00000100;7 96000391C00RETL@0B00000000;8 970003A1C00RETL@0B00000000;9 98;990003B1C00RETL@0B00000000;A 1000003C1C03RETL@0B00000011;b 1010003D1C01RETL@0B00000001;c 1020003E1C06RETL@0B00000110;d 1030003F1C01RETL@0B00000001;E 104000401C0F RETL@0B00001111;F105106;--------------------------------------------------------------10700041LCD2_table:108000410020TBL109000421C02RETL@0B00000010;0 110000431C06RETL@0B00000110;1 111000441C01RETL@0B00000001;2 112000451C04RETL@0B00000100;3 113000461C04RETL@0B00000100;4 114000471C04RETL@0B00000100;5 115000481C00RETL@0B00000000;6 116000491C06RETL@0B00000110;7 1170004A1C00RETL@0B00000000;8 1180004B1C04RETL@0B00000100;9 119;1200004C1C00RETL@0B00000000;A 1210004D1C00RETL@0B00000000;b 1220004E1C03RETL@0B00000011;c 1230004F1C00RETL@0B00000000;d 124000501C01RETL@0B00000001;E 125000511C05RETL@0B00000101;F 126;--------------------------------------------------------------12700052LCD3_table:128000520020TBL129000531C05RETL@0B00000101;0 130000541C07RETL@0B00000111;1131000551C05RETL@0B00000101;2 132000561C05RETL@0B00000101;3 133000571C07RETL@0B00000111;4 134000581C05RETL@0B00000101;5 135000591C05RETL@0B00000101;6 1360005A1C07RETL@0B00000111;7 1370005B1C05RETL@0B00000101;8 1380005C1C05RETL@0B00000101;9 139;1400005D1C07RETL@0B00000111;A 1410005E1C05RETL@0B00000101;b 1420005F1C05RETL@0B00000101;c 143000601C05RETL@0B00000101;d 144000611C05RETL@0B00000101;E 145000621C07RETL@0B00000111;F 146;--------------------------------------------------------------14700063LCD4_table:148000630020TBL149000641C07RETL@0B00000111;0 150000651C01RETL@0B00000001;1 151000661C03RETL@0B00000011;2 152000671C03RETL@0B00000011;3 153000681C05RETL@0B00000101;4 154000691C06RETL@0B00000110;5 1550006A1C06RETL@0B00000110;6 1560006B1C03RETL@0B00000011;7 1570006C1C07RETL@0B00000111;8 1580006D1C07RETL@0B00000111;9 159;1600006E1C07RETL@0B00000111;A 1610006F1C04RETL@0B00000100;b 162000701C06RETL@0B00000110;c 163000711C01RETL@0B00000001;d 164000721C06RETL@0B00000110;E 165000731C00RETL@0B00000000;F 166;------------------------------------16700074LCD5_table:168000740020TBL169000751C05RETL@0B00000101;0 170000761C01RETL@0B00000001;1 171000771C06RETL@0B00000110;2172000781C03RETL@0B00000011;3 173000791C03RETL@0B00000011;4 1740007A1C03RETL@0B00000011;5 1750007B1C07RETL@0B00000111;6 1760007C1C01RETL@0B00000001;7 1770007D1C07RETL@0B00000111;8 1780007E1C03RETL@0B00000011;9179;1800007F1C07RETL@0B00000111;A 181000801C07RETL@0B00000111;b 182000811C04RETL@0B00000100;c 183000821C07RETL@0B00000111;d 184000831C06RETL@0B00000110;E 185000841C06RETL@0B00000110;F186;---------------------------------------------18700085LCD6_table:188000850020TBL189000861C02RETL@0B00000010;0 190000871C00RETL@0B00000000;1 191000881C02RETL@0B00000010;2 192000891C02RETL@0B00000010;3 1930008A1C00RETL@0B00000000;4 1940008B1C02RETL@0B00000010;5 1950008C1C02RETL@0B00000010;6 1960008D1C00RETL@0B00000000;7 1970008E1C02RETL@0B00000010;8 1980008F1C02RETL@0B00000010;9199;200000901C00RETL@0B00000000;A 201000911C02RETL@0B00000010;b 202000921C02RETL@0B00000010;c 203000931C02RETL@0B00000010;d 204000941C02RETL@0B00000010;E 205000951C00RETL@0B00000000;F206;******************************************* 20700096Lcddisplay:208000960F1B jbs sysstatus,lcddsp2090009714B4jmp lcddisplayret21000098091B bc sysstatus,lcddsp211;212000990417mov a,temp_value;2130009A0050mov reg_acc1,a2140009B117B call sub_bintobcd2150009C0412mov a,reg_acc32160009D006B mov temph,a2170009E0411mov a,reg_acc22180009F006A mov tempL,a219;220000A00419mov a,humi_value221000A10050mov reg_acc1,a222000A2117B call sub_bintobcd223000A30412mov a,reg_acc3224000A4006D mov humih,a225000A50411mov a,reg_acc2226000A6006C mov humiL,a227;228000A705E4djz commondata229000A814AB JMP lcddisplay1;$+3 230000A91806MOV a,@(common*2) 231000AA0064MOV commondata,a 232000AB lcddisplay1:233000AB0424MOV a,commondata 234000AC0020TBL235000AD0000NOP236000AE14B5jmp Lcd1display237000AF14D6jmp Lcd2display238000B014F7jmp Lcd3display239000B11518jmp Lcd4display240000B21539jmp lcd5display241000B3155A jmp lcd6display242000B4lcddisplayret:243000B40012ret244;-----------------------------------------------245;显示LCD1246000B5LCD1display:247000B5042A mov a,tempL;温度个位248000B61030call lcd1_table249000B70066mov temp1,a250;251000B8042B mov a,tempH;温度十位252000B91030call lcd1_table253000BA0067mov temp2,a254000BB0727swapa temp2255000BC0226or a,temp1256000BD0066mov temp1,a257000BE0766swap temp1258;259000BF042C mov a,humiL;湿度个位，260000C01030call lcd1_table261000C10068mov temp3,a262;263000C2042D mov a,humiH;湿度十位264000C31030call lcd1_table265000C40069mov temp4,a266000C50729swapa temp4267000C60228or a,temp3268000C70068mov temp3,a269000C80768swap temp3270;271000C90428mov a,temp3272000CA0047mov port7,a273000CB0426mov a,temp1274000CC0045mov port5,a275;276000CD0016ior ioc6277000CE1A0F and a,@0x0f278000CF1960or a,@0b01100000279000D00006iow ioc6;com1:2:3:2.5v 280000D10406mov a,port6281000D21A0F and a,@0x0f282000D31910or a,@0b00010000283000D40046mov port6,a284000D50012ret285;--------------------------------------------286000D6lcd2display:287000D6042A mov a,tempL;温度个位288000D71041call LCD2_table289000D80066mov temp1,a290;291000D9042B mov a,temph;温度十位292000DA1041call LCD2_table293000DB0067mov temp2,a294000DC0727swapa temp2295000DD0226or a,temp1296000DE0066mov temp1,a297000DF0766swap temp1298;299000E0042C mov a,humiL;湿度个位，300000E11041call LCD2_table301000E20068mov temp3,a302;303000E3042D mov a,humih;湿度十位304000E41041call LCD2_table305000E50069mov temp4,a306000E60729swapa temp4307000E70228or a,temp3308000E80068mov temp3,a309000E90768swap temp3310;311000EA0428mov a,temp3312000EB0047mov port7,a313000EC0426mov a,temp1314000ED0045mov port5,a315;316000EE0016ior ioc6317000EF1A0F and a,@0x0f318000F01950or a,@0b01010000319000F10006iow ioc6;com1:2:3:2.5v 320000F20406mov a,port6321000F31A0F and a,@0x0f322000F41920or a,@0b00100000323000F50046mov port6,a324000F60012ret325;-------326000F7lcd3display:327000F7042A mov a,tempL;温度个位328000F81052call LCD3_table329000F90066mov temp1,a330;331000FA042B mov a,temph;温度十位332000FB1052call LCD3_table333000FC0067mov temp2,a334000FD0727swapa temp2335000FE0226or a,temp1336000FF0066mov temp1,a337001000766swap temp1338;33900101042C mov a,humiL;湿度个位，340001021052call LCD3_table341001030068mov temp3,a342;34300104042D mov a,humih;湿度十位344001051052call LCD3_table345001060069mov temp4,a346001070729swapa temp4347001080228or a,temp3348001090068mov temp3,a3490010A0768swap temp3350;3510010B0428mov a,temp33520010C0047mov port7,a3530010D0426mov a,temp13540010E0045mov port5,a355;3560010F0016ior ioc6357001101A0F and a,@0x0f358001111930or a,@0b00110000359001120006iow ioc6;com1:2:3:5v 360001130406mov a,port6361001141A0F and a,@0x0f362001151940or a,@0b01000000363001160046mov port6,a364001170012ret365;------36600118lcd4display:36700118042A mov a,tempL;温度个位368001191063call lcd4_table3690011A0066mov temp1,a370;3710011B042B mov a,temph;温度十位3720011C1063call lcd4_table3730011D0067mov temp2,a3740011E0727swapa temp23750011F0226or a,temp1376001200066mov temp1,a377001210766swap temp1378;37900122042C mov a,humiL;湿度个位，380001231063call lcd4_table381001240068mov temp3,a382;38300125042D mov a,humih;湿度十位384001261063call lcd4_table385001270069mov temp4,a386001280729swapa temp4387001290228or a,temp33880012A0068mov temp3,a3890012B0768swap temp3390;3910012C0428mov a,temp33920012D0047mov port7,a3930012E0426mov a,temp13940012F0045mov port5,a395;396001300016ior ioc6397001311A0F and a,@0x0f398001321960or a,@0b01100000399001330006iow ioc6;com1:2:2.5v,com:2.5V 400001340406mov a,port6401001351A0F and a,@0x0f402001361900or a,@0b00000000403001370046mov port6,a404001380012ret405;--------------40600139lcd5display:40700139042A mov a,tempL;温度个位4080013A1074call lcd5_table4090013B0066mov temp1,a410;4110013C042B mov a,temph;温度十位4120013D1074call lcd5_table4130013E0067mov temp2,a4140013F0727swapa temp2415001400226or a,temp1416001410066mov temp1,a417001420766swap temp1418;41900143042C mov a,humiL;湿度个位，420001441074call lcd5_table421001450068mov temp3,a422;42300146042D mov a,humih;湿度十位424001471074call lcd5_table425001480069mov temp4,a426001490729swapa temp44270014A0228or a,temp34280014B0068mov temp3,a4290014C0768swap temp3430;4310014D0428mov a,temp34320014E0047mov port7,a4330014F0426mov a,temp1434001500045mov port5,a435;436001510016ior ioc6437001521A0F and a,@0x0f438001531950or a,@0b01010000439001540006iow ioc6;com1:2:0v,com:2.5V 440001550406mov a,port6441001561A0F and a,@0x0f442001571900or a,@0b00000000443001580046mov port6,a444001590012ret445;----------------------------4460015A lcd6display:4470015A042A mov a,tempL;温度个位4480015B1085call lcd6_table4490015C0066mov temp1,a450;4510015D042B mov a,temph;温度十位4520015E1085call lcd6_table4530015F0067mov temp2,a454001600727swapa temp2455001610226or a,temp1456001620066mov temp1,a457001630766swap temp1458;45900164042C mov a,humiL;湿度个位，460001651085call lcd6_table461001660068mov temp3,a462;46300167042D mov a,humih;湿度十位464001681085call lcd6_table465001690069mov temp4,a4660016A0729swapa temp44670016B0228or a,temp34680016C0068mov temp3,a4690016D0768swap temp3470;4710016E0428mov a,temp34720016F0047mov port7,a473001700426mov a,temp1474001710045mov port5,a475;476001720016ior ioc6477001731A0F and a,@0x0f478001741930or a,@0b00110000479001750006iow ioc6;com1:2:2.5v,com:0V 480001760406mov a,port6481001771A0F and a,@0x0f482001781900or a,@0b00000000483001790046mov port6,a4840017A0012ret485;------------------------------------------486;--------------------------------------487;此程式是将小于100的数(reg_acc1)转换为BCD码，488;将高位存放于reg_acc2,低位存入于reg_acc3中。
