Epson STYLUS COLOR 580 Service Manual page 48

EPSON Stylus COLOR 580
2.2.2.5 Reset Circuit
Reset circuits consist of the rest IC (IC6). Reset circuits are mounted on the MAIN
board to monitor the two voltages: +5V for the logic line and +42V for the drive line.
When each circuit detects abnormality on the corresponding line, it outputs a reset
signal to reset CPU (IC1). This function is necessary to prevent the printer from
operating abnormally. This IC monitors both +5V and +45 lines but can reset them
independently. The reset circuits outputs reset signal when +5V line becomes 4.2V or
lower or +42V line becomes 33.2V or lower.
Unlike the previous products, the timer IC is not built in the reset IC and the Lithium
battery also is not equipped on the main board.
.
Figure 2-22. Reset Circuit Block Diagram
Main signal lines are explained below;
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OUT1: Interrupt signal
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OUT2: Reset line
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IN: +42V line monitoring line
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VCC: +5V line monitoring line
Operating Principles
2.2.2.6 EEPROM Control Circuit
Since EEPROM is nonvolatile memory, it keeps written information if the printer
power is turned off. When the printer is turned ON, CPU (IC1) reads data from
EEPROM (IC5) and when the power is turned OFF it stores data to EEPROM.
Information stored in EEPROM is listed below.
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See Table 7-7, "EEPROM Address Map," on page 132 that provides detailed
information on the values stored in EEPROM.
IC1
E01A19NA
EEPROM is connected to CPU with 4 lines and each line has the following function.
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Electrical Circuit Operating Principles
Various ink counter (I/C consumption counter, waste pad counter, etc.)
Mechanical setting value (Head ID, Bi-D adjustment, USB ID, etc.)
Figure 2-23. EEPROM Circuit Diagram
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
IC1
E01A19NA
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