Epson Stylus Color 640 Service Manual page 70

EPSON Stylus Color 440/640/740
2.2.4.3 EEPROM Control Circuits
The EEPROM of Stylus Color 440/640/740 has following contents. Gate
array controls operations of reading data when the power is on and
writing data when the power is off.

Ink consumption (Bk, CMY)

CL counter (Various cleaning operations that are previously
done are memorized)

Destination information

Information of various adjustment values (Bi-D, VH voltage, etc.)

CPSI pass word

Other various setting values by the user
EEPROM is connected to the Gate array by 4 lines and performs
following functions. The figure below shows EEPROM control circuit.

CS: Chip selection signal

CK: Data synchronism clock pulse

DI: Data writing line (serial data) at power off.

DO: Data reading line (serial data) at power on.
+5V
AT93C46
(IC11)
8
Vcc
6
ORG
5
GND
Figure 2-26. EEPROM Control Circuit for Stylus Color 440
Chapter 2 Operating Principles
E05B44
(IC2)
1 127
CS
ECS
2 128
SK
ECK
3 126
DI
ECO
125
4
DO
ECI
+5V
AT93C46
(IC11)
8
Vcc
CS
6
ORG SK
5
DI
GND
DO
Figure 2-27. EEPROM Control Circuit Stylus Color 640
+5V
AT93C46
(IC7)
8
Vcc
CS
6
SK
ORG
5
DI
GND
DO
Figure 2-28. EEPROM Control Circuit for Stylus Color 740
Revision A
E05B43
(IC2)
1 130
ECS
2 129
ECK
3 128
ECO
127
4
ECI
E05B588
(IC2)
1 206
EECS
2 205
EECK
204
3
EECO
203
4
EECI
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