Operation Unit Pcb - Kyocera Mita DC-2560 Service Manual

1AH

2-3-3 Operation unit PCB

SI
SO
SCLK
FSYNC
MPCB
Reset circuit
Figure 2-3-17 Operation unit PCB block diagram
Operation unit PCB (OPPCB) consists of controller ASIC (IC1), key switch matrix, LED
display matrix.
The controller ASIC (IC1) communicates serially with the main PCB (MPCB). It
exchanges key switch operation data and LED display data with the main PCB. The
serial control signals are data sending and receiving signals, the data clock (SCLK)
signal for bit synchronization and the data frame synchronization (FSYNC) signal which
is emitted at every frame.
The controller ASIC (IC1) sends scan signals (KS0 to KS7) to the key switch matrix and
determines the operational state by the data read with the return signal terminals (KIN0
to KIN4).
The controller ASIC (IC1) also emits scan signals (DEG0 - DEG7) and LED display
signals (SEG0 - SEG11) to the LED display matrix to light the LEDs and 7-segment
LEDs according to the LED lighting data received from the main PCB (MPCB).
IC5 of the reset circuit also emits a reset signal to initialize the ASIC at power on or if
the power drops excessively.
2-3-16
OPCB
ASIC
IC1
IC5
Key switch section
KS0~KS7
Key Switch
KIN0~KIN4
LED display section
DEG0~DEG7
7-segment
SEG0~SEG15
LED
LED