EM78P468N LCD显示的应用

二、 三、
编程注意事项 ....................................................................................................... 3 LCD 显示范例程序 ............................................................................................... 3
ELAN MICROELECTRONICS CORPORATION
Headquarters: No. 12, Innovation Road 1 Hsinchu Science Park Hsinchu, Taiwan 308 Tel: +886 3 563-9977 Fax: +886 3 563-9966 http://www.emc.com.tw Hong Kong: Elan (HK) Microelectronics Corporation, Ltd. Flat A, 19F., World Tech Centre 95 How Ming Street, Kwun Tong Kowloon, HONG KONG Tel: +852 2723-3376 Fax: +852 2723-7780 elanhk@emc.com.hk Shenzhen: Elan Microelectronics Shenzhen, Ltd. 3F, SSMEC Bldg., Gaoxin S. Ave. I Shenzhen Hi-tech Industrial Park (South Area), Shenzhen CHINA 518057 Tel: +86 755 2601-0565 Fax: +86 755 2601-0500 USA: Elan Information Technology Group (USA) P.O. Box 601 Cupertino, CA 95015 USA Tel: +1 408 366-8225 Fax: +1 408 366-8225
EM78P468N LCD显示的应用
目
一、
录
相关寄存器 ........................................................................................................... 2
1、 R9（CLDCR：LCD 控制寄存器）·················································································· 2 2、 RA（LCD_ADDR：LCD 地址寄存器） ········································································· 2 3、 RB（LCD_DB：LCD 数据缓存器） ··············································································· 3
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LCDTYPE LCDF1
Bit 7 (BS)：LCD bias 选择位 0：1/2 bias 1：1/3 bias Bit6~Bit5(DS1~DS0)：LCD duty 选择位
DS1 0 0 1 DS0 0 1 LCD duty 1/2 duty 1/3 duty 1/4 duty
Bit4(LCDEN)： LCD 使能位 0：LCD 电路关闭，所有公共驱动段输出设置为低电平 1：LCD 电路打开 Bit2（LCDTYPE） ：LCD 驱动波形选择 0：A 类波形 1：B 类波形 Bit1~Bit0(LCDF1~LCDF0） ：LCD 帧频控制位，一般设置为 “1”

3、 RB（LCD_DB：LCD 数据缓存器）
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3
LCD_D3
Bit 2
LCD_D2
Bit 1
LCD_D1
Bit 0
LCD_D0
Bit3~Bit0(LCD_D3~LCD_D0)：LCD RAM 数据传输寄存器
二、 编程注意事项
在编写液晶显示模块程序时，需要注意以下事项： 1、 duty 和 bias 根据液晶的实际参数来设置， 显示的地址和数据分别通过寄存器 RA 和 RB 来控制，还要特别注意液晶的工作电压，以免造成鬼影等不正常现象； 2、 在编写显示部分程序时，应做到整屏刷新，以避免干扰。
注意: Fs为副频振荡频率
2、 RA（LCD_ADDR：LCD 地址寄存器）
Bit 7 0
2
Bit 6 0
Bit 5 0
Bit 4 LCD_A4
Bit 3 LCD_A3
Bit 2 LCD_A2
Bit 1 LCD_A1
Bit 0 LCD_A0
EM78P468N应用笔记
EM78P468N LCD显示的应用
Bit4~Bit0：LCD RAM 地址
RA (LCD 地址) 00H 01H 02H | 1DH 1EH 1FH 公共驱动 COM3 RB (LCD 数据缓存器) Bits 7 ~4 Bit 3 Bit 2 Bit 1 Bit 0 (LCD_D3) (LCD_D2) (LCD_D1) (LCD_D0) | COM2 COM1 COM0 段 SEG0 SEG1 SEG2 | SEG29 SEG30 SEG31
EM78P468N应用笔记
1
EM78P468N LCD显示的应用
EM78P468N LCD 显示的应用
一、 相关寄存器
1、 R9（CLDCR：LCD 控制寄存器）
Bit 7 BS Bit 6 DS1 Bit 5 DS0 Bit 4 LCDEN Bit 3 -Bit 2 Bit 1 Bit 0 LCDF0
1、 汇编范例： ······················································································································· 3 2、 C 范例： ··························································································································· 8
三、 LCD显示范例程序
1、 汇编范例：
下面程序演示的是 LCD 4 位数字 0-9 的循环显示，程式的 Duty 和 Bias 是根据所使用的 LCD 来设置，以下程式中设置为 1/4 duty 和 1/3 bias，使用 SEG0~SEG11 线，LCD 显示地 址和数据分别是由 LCD_ADDR(RA)和 LCD_DB(RB)控制。另附所使用 LCD 图形。 ;********************************************************* ;LCD 显示屏移除显示 0 到 9 ;********************************************************* ;MCU：EM78P468N ;Oscillator：Fm：4MHz Fs：32.768KHz
Shanghai: Elan Microelectronics Shanghai, Ltd. #23, Zone 115, Lane 572, Bibo Rd. Zhangjiang Hi-Tech Park Shanghai, CHINA 201203 Tel: +86 21 5080-3866 Fax: +86 21 5080-4600
LCDF1 0 0 1 1 LCDF0 0 1 0 1 LCD 帧频(例. *Fs=32.768kHz) 1/2 占空比 Fs/(2562)=64.0 Fs/(2802)=58.5 Fs/(3042)=53.9 Fs/(2322)=70.6 1/3 占空比 Fs/(1723)=63.5 Fs/(1883)=58.0 Fs/(2043)=53.5 Fs/(1563)=70.0 1/4 占空比 Fs/(1284)=64.0 Fs/(1404)=58.5 Fs/(1524)=53.9 Fs/(1164)=70.6
EM78P468N
LCD显示的应用
义隆电子股份有限公司
第一版 2009年6月
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