Eeprom Circuit - Epson LX-1050+ Service Manual

Circuit
2.3.2.7 EEPROM
The EEPROM stores in its memory the current feed position of continuously fed paper, as well as
the current panel settings. This memory is retained even after power is shut off.
be maintained even if power goes off.
Following figure shows the EEPROM circuit. Note that this is external to the CPU's memory space.
be sent is set in CPU Dort PB1, and is fed bit-by-bit to the EEPROM in line with rising pulses from
CPU port PC4'S clock: Data are read, bit-by-bitjin line with falling clock pulses.
The EEPROM receives commands to indicate whether to read or write data,
addresses.
777
Rev. A
ER59256
( 1 c)
3
4
DO
Cs
7
2
TEST CLK
Figure 2-19. EEPROM Circuit
CPU
10
PB 1
9
PBO
22
. PC5
21
T
RI 20
Operating Principles
and to indicate
2-15