Epson 900N, Service Manual

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EPSON Stylus COLOR 900/900N Chapter 2 Operating Principles
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2.3.11 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.
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
consumption for each color. When the printer is turned off, the data and
adjustment values accumulated in the D-RAM are written back to the
EEPROM under the ASIC’s control. Information is transmitted between
the ASIC (IC3) and the EEPROM in serial data format.
Figure 2-24. EEPROM Control Circuit Block Diagram
A d d r e s s
D a t a
A T 9 3 C 5 6 ( I C 7 )
V c c
O R G
G N D
+ 5
5
6
8
C S
S K
D I
D O
E 0 5 A 6 0 ( I C 3 )
E C S
E S K
E D I
E D O
1
2
3
4
2 9
3 0
3 1
3 2
D R A M ( I C 5 )
EEPROM