Sharp FO-DC635U, Service Manual

Page: 74 / 166

FO-DC635U
5 – 8
2.1.5 LC24199B-WJ0-E (IC21): pin-208, 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 con-
trol 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.
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 con-
trol 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.
BUS INTERFACE
(BUS OR CIRCUIT)
PCU(INCLUDE PCL)
INTERFACE BLOCK
NIC BOARD
INTERFACE
LIU CH0,CH1 I/F
SPEAKER CONTROL
SENSOR DETECT
GENERATED INTERRUPT
REQUEST BLOCK
RTC LSI
INTERFACE BLOCK
VERIFICATION STAMP
CONTROL BLOCK
GENERATED BUZZER'S
FREQUENCY BLOCK
ORG SENSOR
DETECT BLOCK
GPIO BLOCK
16BIT
INT
CPU
INTERFACE BLOCK
Fig. 4 LC24199B-WJ0-E BLOCK DIAGRAM