2.3.2 Operating Principles of the Main Control Circuit
The main control circuit of this printer is the C162 MAIN Board. This circuit is controlled by the
16-bit CPU H8/3003 (IC1), running at 14.7456 MHz. This CPU has a unique architecture capable of
handling data on the data bus at either an 8-bit or 16-bit bus width. Because of this, a 16-bit or 8-bit
data bus width-type ROM is used on this board, increasing the internal processing speed. Also, the
CPU has a unique architecture capable of the refresh control function. A 4M DRAM (2 CAS
method) on this board is controlled by the CPU itself. The CPU controls the serial interface control
(RS-422 for Mac).
Gate array E05A96 (IC2) manages printhead drive control, external Centronics
®
parallel I/F,
extension CG board and the control panel, and the controls that create the 4-bit signal for the
carriage or the paper feed motor. (The carriage and paper feed motor are controlled by the current
duty data.)
This board also is equipped with EEPROM 93C46 (IC12) to store certain parameters, such as the
printer mechanism control parameter, default setting parameters, as well as a special counter value
used for printhead (ink management) protection.
The timer, IC NJU6355E (IC7), counts each time the printer is cleaned and keeps track of how long
the printer is not used, thereby allowing the printer to be cleared only when necessary.
CL
K
SD
I
/O
DMAREQ
DRAM (4M)
(IC5)
DRAM (4M)
(IC6)
CG-ROM (4M)
(IC16)
EEPROM
(IC12 )
9 3 C 4 6
(IC8)
M5 19 55 B
V x
NJU635 5E
(Timer
Counter)
(IC7)
(IC13)
PST59 2D
RS-422 Serial I/F
To
A
To
B
From A
From B
C162 MAIN Board
S ED 5 6 2 0
(U1,U2)
SLA7041MS (IC14, 15)
H8/3003
(IC1)
C P U
E0 5 A9 6
(IC2)
CG-ROM (8M)
(IC17)
PROM (4 M)
(IC3)
PROM (8 M)
(IC4)
Note 1
Type B I/F
Note 2
Note 1: IC4 is a 32-pin IC socket only.
Note 2: IC17 is an IC socket only.
(IC17 is only installed in JAPAN version.)
Data Bus
Address Bus
Re fresh
Reset
(Power)
Pan el
Reset
(Logic)
Battery
Pa
ra
lle
l I
/F
(C
e
n
tro
n
ic
s
)
C
a
rr
ia
ge
/
P
a
p
e
r Fe
ed
D
riv
e
S
ign
al
B
la
ck /
C
o
lo
r H
e
a
d
Co
m
m
o
n
a
n
d
No
zz
le
S
e
le
ct
o
r D
riv
e S
ig
nal
Carria ge
Black / Color Head
Common Driver Circuit
Carriage / Paper Feed
Motor Driver
Black 64 Nozzles
Co lor 48 Nozzles
Figure 2-17. Main Control Circuit Block Diagram
Stylus Pro XL
Operating Principles
REV.-A
2-15
Summary of Contents for Stylus Pro XL
Page 1: ...EPSON COLOR INKJET PRINTER Stylus Pro XL SERVICE MANUAL EPSON 4004677 ...
Page 93: ...Rev A 5 i ...
Page 127: ...EPSON ...
