1
LCD module
Hitachi HD44780 controller
Hitachi HD44780 controller
and compatible
Main features
z
5x8 character dot matrix display
z
80x8-bit display RAM
z
64x8-bit character generator RAM
z
4-bit or 8-bit interface
Interface
1
Vss GND
2
VDD Vcc (+5V ± 5%)
3
Vo
Contrast Adjustment
4
RS
Register Select
5
R/W Read / Write
6
E
Enable signal
7-14 DB0-DB7 Data Bus
Timing
Item
min
min
description
Item
@ 2.7-4.5V @ 4.5-5.5V
description
PW
EH
450 ns
230 ns
E hold
t
cycE
1000 ns
500 ns
E cycle
t
AB
60 ns
40 ns
address setup
t
AH
20 ns
10 ns
address hold
t
DBW
195 ns
80 ns
data setup (write)
t
H
10 ns
10 ns
data hold (write)
t
DHR
5 ns
5 ns
data hold (read)
Quick guide for standard write
1.
Set RS and data
2.
Set E
3.
Wait at least PW
EH
4.
Clear E
5.
Wait t
cycE
(initialization is different!!)
ET-LCD port on ET-BASE AVR
ET-CLCD pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
signal
GND +Vcc
Vo
RS
R/W
EN
D0 D1 D2 D3
D4
D5
D6
D7
AVR pin
GND
+Vcc
(LCD
ADJ)
PG4
GND
PD7
GND
GND
GND
GND
PG0 PG1 PG2 PG3
