LCD液晶显示屏设计书一、设计的目的1．学习液晶显示的编程方法，了解液晶显示模块的工作原理。

掌握液晶显示模块与单片机的接口方法。

2.学习和了解微型打印机模块的工作原理。

掌握微型打印机模块与单片机的接口方法。

二、设计的题目和要求编程实现在液晶显示屏上显示且实现打印双行中文汉字“XX大学 XX学院”。

三、设计报告的容3.1、总体实验功能要求设计并实现程序：１、在点阵式LCD模块上双行显示“XX大学 XX学院”。

2、打印机双行打印“大学信息学院”字样。

3.2、实现方案１、LCD液晶显示屏模块在点阵式LCD模块上双行显示“XX大学 XX学院”：硬件接口接口协议为请求/应答（REQ/BUSY）握手方式。

应答 BUSY 高电平（BUSY =1）表示 OCMJ 忙于部处理，不能接收用户命令；BUSY 低电平（BUSY =0）表示 OCMJ空闲，等待接收用户命令。

发送命令到 OCMJ 可在 BUSY =0 后的任意时刻开始，先把用户命令的当前字节放到数据线上，接着发高电平 REQ 信号（REQ =1）通知 OCMJ 请求处理当前数据线上的命令或数据。

OCMJ 模块在收到外部的 REQ 高电平信号后立即读取数据线上的命令或数据，同时将应答线 BUSY 变为高电平，表明模块已收到数据并正在忙于对此数据的部处理，此时，用户对模块的写操作已经完成，用户可以撤消数据线上的信号并可作模块显示以外的其他工作，也可不断地查询应答线 BUSY 是否为低（BUSY =0？），如果BUSY =0，表明模块对用户的写操作已经执行完毕。

可以再送下一个数据。

如向模块发出一个完整的显示汉字的命令，包括坐标及汉字代码在共需 5 个字节，模块在接收到最后一个字节后才开始执行整个命令的部操作，因此，最后一个字节的应答BUSY 高电平（BUSY =1）持续时间较长，具体的时序图和时间参数说明查阅相关手册。

2. 点阵打印机模块打印机双行打印“大学信息学院”字样：进纸按钮：按下时，自动进纸。

启动/停止按钮：向上时，启动打印；向下时，停止打印。

设计实现流程框图如下：3.3、实验模块CPU挂箱对象挂箱接口挂箱CPU模块（80C31）点阵式LCD 模块针式微型打印机模块8251/8255扩展模块 8051CPU模块3.4、系统定义定义CPU挂箱上的K1平推开关为打印机控制开关3.5、实验连线LCD显示模块用串口电缆将串口（DB9）与计算机的COM1相连有关LCD屏显模块的连线1、用导线将 PA.0(CPU模块) 与 DB0(LCD模块) 相连2、用导线将 PA.1(CPU模块) 与DB1(LCD模块) 相连3、用导线将 PA.2(CPU模块) 与DB2(LCD模块) 相连4、用导线将 PA.3(CPU模块) 与DB3(LCD模块) 相连5、用导线将 PA.4(CPU模块) 与DB4(LCD模块) 相连6、用导线将 PA.5(CPU模块) 与DB5(LCD模块) 相连7、用导线将 PA.6(CPU模块) 与DB6(LCD模块) 相连8、用导线将 PA.7(CPU模块) 与DB7(LCD模块) 相连9、用导线将 PC7(CPU模块) 与BUSY(LCD模块) 相连10、用导线将 PC0(CPU模块) 与REQ(LCD模块) 相连片选信号CS8255 选择 CS0。

针式微型打印机模块有关打印机模块的连线1、用导线将 P1.0(CPU模块) 与RESET(PRINTER模块) 相连2、用导线将 P1.1(CPU模块) 与TIMEDETECT(PRINTER模块) 相连3、用导线将 P1.2(CPU模块) 与PRINTPOWER(PRINTER模块) 相连4、用导线将 P1.3(CPU模块) 与PSA(PRINTER模块) 相连5、用导线将 P1.4(CPU模块) 与PSB(PRINTER模块) 相连6、用导线将 P1.5(CPU模块) 与PSC(PRINTER模块) 相连7、用导线将 P1.6(CPU模块) 与PSD(PRINTER模块) 相连8、用导线将 P1.7(CPU模块) 与K1(CPU挂箱) 相连3.6、实验现象观察与调试1、首先检查连线，保证连线正确，然后给系统加电。

2、上位机运行8051的上位机程序，系统连接正常后，打开试验程序WXDYJJLCDKZ.ASM经编译、连接后，全速运行程序（根据需要可单步运行、单步跟踪、设置断点）。

3、LCD显示模块：程序全速运行后，在LCD模块显示“大学信息学院”。

4、打印：打印机模块上有一个进纸按钮：按下时，自动进纸。

K1是启动/停止按钮：向上时，启动打印；向下时，停止打印。

打印出两行字“大学信息学院”。

四、结论8255扩展模块是一种常用的可编程并行 I/O 接口芯片，片有 PA、PB、PC 三个 8 位可编程双向通用扩展I/O 口。

控制线控制8255的读、写、复位及片选等：RD：读控制线，低电平有效，当其为低电平时，CPU对 8255 进行读操作，此时 8255相应口为输入口。

WR：写控制线，低电平有效，当其为低电平时，CPU输出数据或命令到8255端口，此时8255相应口为输出口。

RESET：复位端，高电平有效。

当其为高电平时，8255部寄存器全部清零，24 条I/O 口线为高阻态。

CS：片选端，低电平有效。

当其为低电平时，CPU选中此 8255芯片。

通过CPU模块的控制LCD、打印机模块，使其发挥相应的功能，完成CPU 控制的总功能。

五、参考文献[1] 迎新，等. 单片机初级教程[M]..航空航天大学，2000.[2] 何立民. MCS-51系列单片机应用系统设计配置与接口技术[M] ..航空航天大学，1990.[3] 孟利利 MCS-51系列单片机应用实验课程报告《微型打印机及LCD控制实验》，2011.附录：程序代码;correctCSEG AT 4000H LJMP STARTCSEG AT 4100HSTART: MOV P1, #0FFH START1: MOV 20H, #00H MOV 21H, #00H MOV 50H,20H LCALL DELAY100M MOV R5,#08HMOV R6,#90HMOV R7,#2MOV R1,#0JNB P1.7,PRINT603LJMP START1PRINT603: MOV A,20HJB ACC.0,PRINT51CLR P1.2PRINT50: LCALL PRINTLINEMOV R7,#33HDJNZ R5,PRINT50NOPSETB P1.2LCALL DELAY100MMOV R5,#8CLR P1.2PRINT51: LCALL PRINTLINEMOV R7,#33HDJNZ R5,PRINT51NOPSETB P1.2LCALL DELAY100MMOV R5,#7CLR P1.2 PRINT52: LCALL PRINTLINEMOV R7,#33HDJNZ R5,PRINT52NOPSETB P1.2LCALL DELAY100MLJMP START100DELAY100M: MOV R6, #40 ;60ms DEL1: MOV R7, #250DEL2: NOPNOPDJNZ R7, DEL2DJNZ R6, DEL1RETWAIT: CLR AMOV C,P1.1RLC AMOV 41H,AMOV 50H,AXRL A,40HJZ WAITMOV 40H,41HMOV 50H,41HRETPRINTLINE: NOPJNB P1.0,PRINTLINE MOV R2, #60HMOV R3,#00H CLR AMOV C,P1.1RLC AMOV 40H,AMOV 50H,40H LCALL WAITPRINT300: MOV DPTR,#TABLE11 LCALL PRINT1MOV DPTR,#TABLE12 LCALL PRINT2MOV DPTR,#TABLE13 LCALL PRINT3MOV DPTR,#TABLE14 LCALL PRINT4INC R3MOV A,R3CJNE A,#8,PRINT300 MOV R3,#0INC R1DEC R7MOV A,R2JNZ PRINT300NOPRETPRINT1: MOV A,R3JNZ PRINT400MOV A, R1MOVC A, A+DPTRMOV 43H,APRINT400: MOV A,43HJNB ACC.7, PRINT111 CLR P1.3LCALL WAITSETB P1.3LJMP PRINT311PRINT111: LCALL WAIT PRINT311: MOV A,43HRL AMOV 43H,AMOV 50H,43HRETPRINT2: DEC R2MOV A,R3JNZ PRINT401MOV A,R1MOVC A,A+DPTRMOV 44H,APRINT401: MOV A,44HJNB ACC.7,PRINT11CLR P1.4LCALL WAITSETB P1.4LJMP PRINT312 PRINT11: LCALL WAIT PRINT312: MOV A,44HRL AMOV 44H,AMOV 50H,44H RETPRINT3: DEC R2MOV A,R3JNZ PRINT402 MOV A,R1MOVC A,A+DPTRMOV 45H,APRINT402: MOV A,45HJNB ACC.7,PRINT21 CLR P1.5LCALL WAITSETB P1.5LJMP PRINT313PRINT21: LCALL WAITPRINT313: MOV A,45HRL AMOV 45H,AMOV 50H,45HRETPRINT4: DEC R2MOV A,R3JNZ PRINT403MOV A,R1MOVC A,A+DPTRMOV 46H,APRINT403: MOV A,46HJNB ACC.7,PRINTEND CLR P1.6LCALL WAITSETB P1.6LJMP PRINT314PRINTEND: LCALL WAITPRINT314: MOV A,46HRL AMOV 46H,AMOV 50H,46HDEC R2INC R7RETTABLE12: DB 00H,00H,00H,00H,00H,00H,10H,00H,00H,0CH,00H,78H,04H,1FH,80H,04HDB10H,00H,00H,90H,00H,01H,10H,00H,21H,10H,00H,32H,10H,0CH,12H,1FHDB0F0H,12H,10H,40H,04H,10H,40H,04H,10H,40H,04H,30H,40H,08H,30H,40H DB78H,20H,40H,18H,20H,40H,18H,60H,40H,18H,40H,40H,18H,80H,40H,19HDB 00H,40H,02H,00H,40H,00H,00H,00HTABLE11: DB 00H,00H,00H,00H,00H,00H,03H,86H,00H,01H,06H,00H,01H,0CH,00H,31HDB08H,08H,31H,0FH,0FCH,11H,10H,00H,11H,12H,00H,11H,21H,80H,11H,40H DB0C0H,11H,80H,40H,11H,00H,08H,11H,1FH,0FCH,11H,11H,88H,11H,11H,88HDB11H,11H,88H,31H,11H,88H,31H,11H,88H,21H,11H,88H,01H,1FH,0F8H,01H DB 10H,08H,01H,10H,08H,02H,00H,00HTABLE13: DB00H,00H,00H,00H,00H,00H,00H,18H,00H,00H,10H,00H,00H,10H,00H,00H10H,00H,00H,10H,00H,00H,10H,0CH,3FH,0FFH,0FEH,00H,10H,00H,00H,18 HDB00H,00H,18H,00H,00H,34H,00H,00H,34H,00H,00H,22H,00H,00H,22H,00H DB00H,41H,00H,00H,0C1H,80H,00H,80H,0C0H,01H,00H,60H,02H,00H,38H,0C HDB 00H,1CH,30H,00H,08H,00H,00H,00HTABLE14: DB00H,00H,00H,00H,00H,00H,04H,20H,60H,02H,10H,40H,03H,18H,0C0H,01H DB18H,80H,01H,11H,00H,10H,02H,0CH,1FH,0FDH,0FEH,10H,00H,18H,30H,00 HDB0A0H,27H,0FFH,0C0H,00H,03H,00H,00H,04H,00H,00H,18H,00H,00H,18H,1 8H3FH,0FFH,0E0H,00H,18H,00H,00H,18H,00H,00H,18H,00H,00H,18H,00H,00 HDB 0F8H,00H,00H,30H,00H,00H,00H,00HSTART100: MOV 20H, #00HMOV 21H, #00HMOV 50H,20HLCALL DELAY200MMOV R5,#08HMOV R6,#90HMOV R7,#2MOV R1,#0JNB P1.7,PRINT6032LJMP START1PRINT6032: MOV A,20HJB ACC.0,PRINT512CLR P1.2PRINT502: LCALL PRINTLINE2MOV R7,#33HDJNZ R5,PRINT502NOPSETB P1.2LCALL DELAY200MMOV R5,#8CLR P1.2 PRINT512: LCALL PRINTLINE2MOV R7,#33HDJNZ R5,PRINT512NOPSETB P1.2LCALL DELAY200MMOV R5,#7CLR P1.2 PRINT522: LCALL PRINTLINE2MOV R7,#33HDJNZ R5,PRINT522NOPSETB P1.2LCALL DELAY200MLJMP START1DELAY200M: MOV R6, #40 ;60ms DEL12: MOV R7, #250DEL22: NOPNOPDJNZ R7, DEL22 DJNZ R6, DEL12 RETWAIT2: CLR AMOV C,P1.1RLC AMOV 41H,AMOV 50H,AXRL A,40HJZ WAIT2MOV 40H,41HMOV 50H,41HRETPRINTLINE2: NOPJNB P1.0,PRINTLINE2MOV R2, #60HMOV R3,#00HCLR AMOV C,P1.1RLC AMOV 40H,AMOV 50H,40HLCALL WAITPRINT3002: MOV DPTR,#TABLE21 LCALL PRINT12MOV DPTR,#TABLE22 LCALL PRINT22MOV DPTR,#TABLE23 LCALL PRINT32MOV DPTR,#TABLE24 LCALL PRINT42INC R3MOV A,R3CJNE A,#8,PRINT3002 MOV R3,#0INC R1DEC R7MOV A,R2JNZ PRINT3002NOPRETJNZ PRINT4002MOV A, R1MOVC A, A+DPTRMOV 43H,APRINT4002: MOV A,43HJNB ACC.7, PRINT1112 CLR P1.3LCALL WAITSETB P1.3LJMP PRINT3112PRINT1112: LCALL WAITPRINT3112: MOV A,43HRL AMOV 43H,ARETPRINT22: DEC R2MOV A,R3JNZ PRINT4012MOV A,R1MOVC A,A+DPTRMOV 44H,APRINT4012: MOV A,44HJNB ACC.7,PRINT112 CLR P1.4LCALL WAITSETB P1.4LJMP PRINT3122PRINT112: LCALL WAIT PRINT3122: MOV A,44HRL AMOV 44H,AMOV 50H,44HRETPRINT32: DEC R2MOV A,R3JNZ PRINT4022MOV A,R1MOVC A,A+DPTRMOV 45H,APRINT4022: MOV A,45HJNB ACC.7,PRINT212CLR P1.5LCALL WAITSETB P1.5LJMP PRINT3132PRINT212: LCALL WAITPRINT3132: MOV A,45HRL AMOV 45H,AMOV 50H,45H RETPRINT42: DEC R2MOV A,R3JNZ PRINT4032 MOV A,R1MOVC A,A+DPTRMOV 46H,APRINT4032: MOV A,46HJNB ACC.7,PRINTEND2 CLR P1.6LCALL WAITSETB P1.6LJMP PRINT3142PRINTEND2: LCALL WAITPRINT3142: MOV A,46HRL AMOV 46H,AMOV 50H,46HDEC R2INC R7TABLE23: DB 00H,00H,00H,00H,00H,00H,10H,00H,00H,0CH,00H,78H,04H,1FH,80H,04HDB10H,00H,00H,90H,00H,01H,10H,00H,21H,10H,00H,32H,10H,0CH,12H,1FHDB0F0H,12H,10H,40H,04H,10H,40H,04H,10H,40H,04H,30H,40H,08H,30H,40H DB78H,20H,40H,18H,20H,40H,18H,60H,40H,18H,40H,40H,18H,80H,40H,19HDB 00H,40H,02H,00H,40H,00H,00H,00HTABLE24: DB 00H,00H,00H,00H,00H,00H,03H,86H,00H,01H,06H,00H,01H,0CH,00H,31HDB08H,08H,31H,0FH,0FCH,11H,10H,00H,11H,12H,00H,11H,21H,80H,11H,40H0C0H,11H,80H,40H,11H,00H,08H,11H,1FH,0FCH,11H,11H,88H,11H,11H,88 HDB11H,11H,88H,31H,11H,88H,31H,11H,88H,21H,11H,88H,01H,1FH,0F8H,01H DB 10H,08H,01H,10H,08H,02H,00H,00HTABLE22: DB00H,00H,00H,00H,00H,00H,00H,18H,00H,00H,10H,00H,00H,10H,00H,00H DB10H,00H,00H,10H,00H,00H,10H,0CH,3FH,0FFH,0FEH,00H,10H,00H,00H,18 HDB00H,00H,18H,00H,00H,34H,00H,00H,34H,00H,00H,22H,00H,00H,22H,00H DB00H,41H,00H,00H,0C1H,80H,00H,80H,0C0H,01H,00H,60H,02H,00H,38H,0C HDB 00H,1CH,30H,00H,08H,00H,00H,00HTABLE21: DB00H,00H,00H,00H,00H,00H,04H,20H,60H,02H,10H,40H,03H,18H,0C0H,01HDB18H,80H,01H,11H,00H,10H,02H,0CH,1FH,0FDH,0FEH,10H,00H,18H,30H,00HDB0A0H,27H,0FFH,0C0H,00H,03H,00H,00H,04H,00H,00H,18H,00H,00H,18H,18HDB3FH,0FFH,0E0H,00H,18H,00H,00H,18H,00H,00H,18H,00H,00H,18H,00H,00HDB 0F8H,00H,00H,30H,00H,00H,00H,00H END。