Sharp FO 4400 - B/W Laser - All-in-One Service Manual page 98

FO-4400U
FO-CS1
5) LC24199B-WJ0-E (IC21): pin-216, QFP (SUB ASIC)
The device is the gate-array, which has the following functions.
1
PCU (Print Control Unit) interface
The block has the serial communication to PCU, and using this cir-
cuitry, controls/detects PCU.
2
I/O port
The block has the following functions; LIU interface, Speaker control
and sensor detect, which are controlled with software.
3
Generator of buzzer's frequency
The block has the generated buzzer's frequency by the software.
INTERFACE BLOCK
16BIT
BUS INTERFACE
(BUS OR CIRCUIT)
INT
GENERATED INTERRUPT
REQUEST BLOCK
RTC LSI
INTERFACE BLOCK
VERIFICATION STAMP
CONTROL BLOCK
GENERATED BUZZER'S
FREQUENCY BLOCK
ORG SENSOR
DETECT BLOCK
Fig. 4 LC24199B-WJ0-E BLOCK DIAGRAM
4
RTC (Real Time Clock) LSI control
Using serial communication to RTC, the device set and read the time.
5
Verification stamp control
The software control on/off of the verification stamp. And the control
block has hardware timer instead of the continuous stamp-on status.
6
Original sensor detect
The software detects the original sensor. And then the control block
has the generated interrupt circuitry by detecting the sensor signal
risen/fallen.
CPU
PCU(INCLUDE PCL)
INTERFACE BLOCK
NIC BOARD
INTERFACE
GPIO BLOCK
LIU CH0,CH1 I/F
SPEAKER CONTROL
SENSOR DETECT
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