REV.-B
Table 2-5. Functions of the Main
and Circuits (Cont.)
or Circuit
Location
Functions
2A
This is a
single
chip that houses drive circuits for the printhead,
and MOTOR, PF of the PRINTER MECHANISM. The chip also includes the
various sensor input circuits for the PRINTER MECHANISM.
PROM
5E
PROM contains the program that runs the CPU.
RAM
6E
Holds the CPU working area and the various buffers. (1 E is not used for
an 80-column device and is not installed.)
MROM
3E
Holds the character design (also called the character generator).
(Mask ROM)
4E
is an electronically writable and erasable ROM used to hold such
information as the TOF position.
Vref Circuit
—
This is a circuit for generating the reference voltage used in the A/D
convertor within the CPU.
2.3.2
Reset
Circuit
Figure 2-19 shows the reset circuit in block diagram form. The reset circuit issues the RESET signal.
Each part of the control circuits is initialized when this
is received. The conditions when
the RESET signal is output are described below.
When turning on the power supply
Immediately after
the power has been turned on,
(2A) outputs the
pulse.
receives this pulse and then outputs the DISC pulse. The electrical charge in the condenser within
the
is then discharged. After this, STK-6022”B outputs the
signal, and
then
outputs the RESET signal. After a certain time has elapsed, the charge in the condenser in the
builds up again. The
signal is canceled and then the RESET signal is canceled.
Resets performed by the CPU itself (CPU self-reset)
The CPU outputs the RESET signal if there is a RESET request for
and if
has output
the DISC pulse.
+5
L i n e
(2A)
- - - - - - - - - - -
- - - - - - - - - - -
75
107
7 3
106
—
—
DISC
’
0
5
Figure 2-19. Reset Circuit Block Diagram
2-15
Summary of Contents for LQ-1070+
Page 1: ...EPSON TERMINAL PRINTER LG1 570 lo7cJ L 4000566 REV B ...
Page 111: ...REV A Figure 6 2 LQ 570 Lubrication Points 6 3 ...
Page 112: ...REV B 6 4 ...
Page 125: ...REV B C3 11 C9 I 1 Figure A 10 BOARD ASSY POWER SUPPLY C062 PSB BOARD Component Layout A 1 3 ...
Page 127: ...REV B Zluo Zr Vlr alr Figure A 1 2 BOARD ASSY PANEL C062 PNL BOARD Component Layout A 1 5 ...
Page 128: ...Figure A 1 3 LQ 570 Exploded Diagram A 1 6 ...
Page 129: ...REV B A 1 9 ...
Page 133: ... I C 71 I Ila u 4 l t mm 151 m Figure A 1 8 LQ 107O Case Outline Drawing A 23 ...
Page 135: ...EPSON Printed in Japan 91 09 5 G ...