Datasheet
DEM 16214 FGH-PW    Product Specification       
Version: 2      PAGE:4 
4. BLOCK DIAGRAM 
VSS
VDD
V0
RS
R/ W
E
DB 0
~
DB 7
ST7066U-0A
COM1~16
L CD  PANEL
2Li neX16Char act er s
SEG0~40
SEG41~8
0
ST7065C
B/ L
A
K
5. PIN ASSIGNMENT 
Pin No.  Symbol  Function 
1  VSS  Ground terminal of module. 
2  VDD  Supply terminal of module 5.0V. 
3  V0  Power Supply for liquid crystal drive. 
4 RS 
Register select 
RS = 0 (Instruction register) 
RS = 1 (Data register) 
5 R/W 
Read /Write 
R/W = 1 (Read) 
R/W = 0 (Write) 
6 E Enable 
7 DB0 
8 DB1 
9 DB2 
10 DB3 
11 DB4 
12 DB5 
13 DB6 
14 DB7 
Bi-directional data bus, data transfer is performed once, thru DB0 to DB7, in 
the case of interface data. Length is 8-
b
its; and twice, thru DB4 to DB7 in the 
case of interface data length is 4-bits. Upper four bits first then lower four bits. 
15  LED – (K)  Please also refer to 6.1 PCB drawing and description. 
16  LED + (A)  Please also refer to 6.1 PCB drawing and description. 










