EPSON Stylus Color 900 Revision C
Operating Principles Electrical Circuit Operation Principles 77
2.3.9 EEPROM Control Driver Circuit
Data for various factory-adjustment items is stored in the EEPROM
(IC7) on the C265 main board. The size of the EEPROM is 2 K bit since
various types of dots are available with this printer and memory
allocated for the ink consumption counter is accordingly large.
When the printer is turned on, data stored in the EEPROM is transferred
to the D-RAM by the ASIC (IC3). In the D-RAM, the ASIC controls
various adjustment values, total ink consumption, and current ink usage
condition for each color, and the printer prints depending on these
values. When the printer is turned off, the data and adjustment values
accumulated and controlled in the D-RAM are written back into the
specific addresses in the EEPROM under the ASIC’s control.
Information is transmitted between the ASIC (IC3) and the EEPROM in
the serial data format.
Figure 2-22. EEPROM Control Circuit Block Diagram
Address
Data
AT93C 56(IC7)
Vcc
ORG
GND
+5
5
6
8
CS
SK
DI
DO
E05A60(IC 3)
ECS
ESK
EDI
EDO
1
2
3
4
29
30
31
32
DRAM(IC5)
