Specifications

4–30 EPSON
SED1220
up to 5 icons (SED1220/1221/1222) or 10 icons
(SED122A).
Following shows relationship between the static icons
functions, static icon RAM addresses and written data.
Electronic Volume RAM (register)
SED1220 contains the electronic volume function for
controlling the liquid crystal drive voltage V5 and density
of liquid crystal display. The electronic volume function
enables to select one of 32 voltage status of the liquid
crystal drive voltage V5 by writting 5-bit data to the
electronic volume RAM.
Following shows relationship between RAM addresses
set by the electronic volume and written data.
Function
< SEGSF, G, H, I, J >
RAM address
Static icon data
D7 D0 S E G S F G H I J
Display
On/Off
22H
23H
Blink
On/Off
00111
***
1000
Display
1
***
*: Blank
1: Display or blink on
0: Display or blink off
f
BLINK: 1–2 Hz
f BLINK
Function
< SEGSA, B, C, D, E >
RAM address
Static icon data
D7 D0 S E G S A B C D E
Display
On/Off
20H
21H
Blink
On/Off
00111
***
1000
Display
1
***
f BLINK
Function RAM address
Electronic volume data
Condi-
tion
V
EV
Electronic
volume data
28H
29H
V
REG –0
V
REG –α
V
REG –2α
V
REG –29α
V
REG –30α
V
REG –31α
For testing
0
D7 D0
00000
***
110000
***
200000
***
2910111
***
3001111
***
3111111
***
*****
·· ·· ·· ··
* : Blank
Note : Do not use the address “29H”. It is for testing
α = V
REG /150
Static Icon Ram
SED1220 contains the static icon RAM for displaying
the static icons in addition to the dynamic icons.
Capacity of static icon RAM is 10 bits (SED1220/1221/
1222) or 20 bit (SED122A) and is capable of displaying