Reset Circuit; Eeprom Control Circuit - Epson Stylus C 60 Service Manual

EPSON Stylus C60

2.2.2.5 Reset Circuit

Reset IC (IC2) on the MAIN board monitors the two voltage: +5V for the logic line
and +42V for the drive line. Reset IC outputs the reset signal to CPU (IC1) in the
following case.
1. When the printer power is turned on and reset IC detects 4.2V on +5V line/36.3V
on +42V line, reset signal is output to perform the initialize operation correctly.
2. When the printer power is turned off and reset IC detects 4.2V on +5V line/36.3V
on +42V line, reset signal is output to stop the printer operation safely.
3. When reset IC detects 4.2V on +5V line/36.3V on +42V line with fail during the
printer operation, reset signal is output to stop the printer operation safely.
Unlike the previous products, the timer IC is not built in the reset IC and the Lithium
battery is not mounted on this MAIN board either.
+42V
BH6150F-E2
1
NC1
2
IN
3
NC2
4
GND
Figure 2-21. Reset circuit block diagram
Main line for reset IC has the following function.
OUT1: Interrupt signal
OUT2: Reset line
IN: +42V line monitoring line
VCC: +5V line monitoring line
Operating Principles
.
+5V
IC2
IC1
E01A24CA
38
8
MRES
MEWS
7
VCC
37
6
NMI
OUT1
36
5
RESET
OUT2
Electrical Circuit Operating Principles

2.2.2.6 EEPROM Control Circuit

When the printer power is turned off, the following information is stored in EEPROM
(IC3) which is nonvolatile memory. And, when the printer power is on, CPU (IC1)
reads the information from EEPROM.
Information stored in EEPROM is listed below.
Various ink counter (I/C consumption counter, waste pad counter, etc.)
Mechanical setting value (Head ID, Bi-D adjustment, USB ID, etc.)
Refer to 7.1.2 that provides the detailed information stored in EEPROM.
EEPROM-93C
+5V
(IC3)
8
VCC
7
NC
6
ORG
5
GND
Figure 2-22. EEPROM circuit diagram
EEPROM is connected to CPU with 4 lines and each line has the following function.
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.
Revision A
E01A24CA
(IC1)
1
42
CS
C-P20
2
41
SK
C-P21
3
40
DI
C-P22
4
39
DO
C-P23
44