l8h35
8h35row1_val8h36
8h36row1_val8h37
8h37row1_val8h38
8h38row1_val8h39
8h39row1_val8h30
defaultrow1_val8h30
e
dcase
e
d
parameterIDLE
8h00
parameterDISP_SET8h01
显示模式设置
parameterDISP_OFF8h03
显示关闭
parameterCLR_SCR
8h02
显示清屏
parameterCURSOR_SET18h06
显示光标移动设置
parameterCURSOR_SET28h07
显示开及光标设置
parameterROW1_ADDR8h05
写第1行起始地址
parameterROW1_0
8h04
reg50curre
t_state
ext_state现态、次态
alwaysposedgelcd_clk
egedgerst_

3
fLCD1602液晶显示实验报告
ifrst_
curre
t_stateIDLE
else
curre
t_state
ext_state在时钟信号作用期间，次态重复
的赋给现态
always
begi

casecurre
t_state
IDLE

ext_stateDISP_SET
DISP_SET
ext_stateDISP_OFF
DISP_OFF
ext_stateCLR_SCR
CLR_SCR
ext_stateCURSOR_SET1
CURSOR_SET1
ext_stateCURSOR_SET2
CURSOR_SET2
ext_stateROW1_ADDR
ROW1_ADDR
ext_stateROW1_0
ROW1_0

ext_stateROW1_ADDR
default
ext_stateIDLE
e
dcase
e
d
alwaysposedgelcd_clk
egedgerst_

begi

ifrst_

begi

lcd_rs0
lcd_data8hxx
e
d
else
begi

case
ext_state
IDLE
lcd_rs0
DISP_SET
lcd_rs0
DISP_OFF
lcd_rs0
CLR_SCR
lcd_rs0
CURSOR_SET1lcd_rs0
CURSOR_SET2lcd_rs0
ROW1_ADDRlcd_rs0
ROW1_0
lcd_rs1
e
dcase
case
ext_state
IDLE
lcd_data8hxx
DISP_SET
lcd_data8h38
DISP_OFF
lcd_data8h08
CLR_SCR
lcd_data8h01
CURSOR_SET1lcd_data8h04
CURSOR_SET2lcd_data8h0C
ROW1_ADDRlcd_data8h80
4
fLCD1602液晶显示实验报告
ROW1_0e
dcasee
de
dassig
lcd_elcd_clkassig
lcd_rw1b0e
dmodule
lcd_datarow1_val127120
数据在时钟高电平被锁存只写
5下载电路及引脚分配设计
设计中用实验箱自带的50MHz时钟信号作为输入端，用sel0、sel1、sel2三个使能端选通LCD1602液晶屏，EP2C8Q208C8就会工作在给液晶下命令的状态，使得点阵正常工作，如图351所示。
图351输入输出端口电路引脚分配设计如图352所示。
图352引脚分配
5
fLCD1602液晶显示实验报告
四、实验仿真及结论1液晶显示仿真波形
液晶显示仿真波形如图411所示。
图411仿真波形通过仿真可以看到，液晶的状态转换是：IDLE00HDISP_SET38H显示模式设置DISP_OFF08H显示关闭CLR_SCR01H显示清屏
CURSOR_SET104H显示光标移动位置CURSOR_SET20CH显示开关及光标设置ROW1_ADDR80H写第一行起始地址333H80H434H80H434H80H536H80H636H80H636H80H737H80H838H80H838H80H
939H80H030H……后面的数字就可依次循环了，直到拨码开关r