Specifications
4–12 EPSON
SED1220
Pin name I/O Description Q’ty
D7 (SI) I 8-bit input data bus. These pins are connected to a 8-bit or 16-bit 8
D6 (SCL) standard MPU data bus.
D5 ~ D0 When P/S = “Low”, the D7 and D6 pins are operated as a serial data
input and a serial clock input respectively.
A0 I Usually, this pin connects the least significant bit of the MPU address 1
bus and identifies a data command.
0 : Indicates that D0 to D7 are a command.
1 : Indicates that D0 to D7 are display data.
RES I In case of a 68 series MPU, initialization can be performed by 1
changing RES
. In case of an 80 series MPU,
initialization can be performed by changing
.
A reset operation is performed by edge sensing of the RES signal.
An interface type for the 68/80 series MPU is selected by input level
after initialization.
“L” : 68 series MPU interface
“H” : 80 series MPU interface
CS I Chip select signal. Usually, this pin inputs the signal obtained by 1
decoding an address bus signal. At the “Low” level, this pin is
enabled.
WR I <When connecting an 80 series MPU>
Active “Low”. This pin connects the WR signal of the 80 series 1
(E) MPU. The signal on the data bus is fetched at the rise of the WR
signal.
<When connecting a 68 series MPU>
Active “High”. This pin becomes an enable clock input of the 68
series MPU.
P/S I This pin switches between serial data input and parallel data input. 1
IF I Interface data length select pin for parallel data input. 1
“High”: 8-bit parallel input
“Low”: 4-bit parallel input
When P/S = “Low”, connect this pin to V
DD or VSS.
CK I External input terminal
It must be fixed to “High” when the internal oscillation circuit is used. 1
Pins for System Bus Connection
P/S RES I/F D7 D6 D5 D4 D3-D0 CS A0 WR
“L” — — SI SCL — — OPEN CS A0 —
“H” “H” “H” D7 D6 D5 D4 D3-D0 CS A0 E
“H” “L” “H” D7 D6 D5 D4 D3-D0 CS A0 WR
“H” “L” “L” D7 D6 D5 D4 OPEN CS A0 WR
P/S
Chip Select Data/Command
Data Serial Clock
“High” CS A0 D0~D7 –
“Low” CS A0 SI SCL
RES: Indicates the active potential.
OPEN:Though “OPEN” is available, fixing the potential is
recommended for noise-withstnading characteristical reason.
—: Indicates that it can be set at either “H” or “L”, but fixing the
potential is required.