No. 5342-11/34
LC78631E
4. Command input
An external controller can execute LC78631E instructions by setting RWC high and inputting commands to COIN in
synchronization with the CQCK clock. Commands are executed on the fall of the RWC signal.
Single-byte commands
Two-byte commands
Command noise reduction
This command can reduce the noise on the CQCK clock signal. While this is effective for noise pulses under
500 ns, the use of this function requires that the CQCK timings tWL, tWH, and tSU (see Figure 1 and 2) be set to
1 s or longer.
5. CLV servo circuit
CLV servo circuit; Pin 13: CLV+, pin 14: CLV–, pin 15: V/P
The CLV+ signal causes the disc to accelerate in the forward direction, and CLV– causes the disc to decelerate. The
microcontroller can select one of four modes: accelerate, decelerate, CLV, and stop. The table below lists the states
of the CLV+ and CLV– pins in each of these modes.
Note: The CLV servo control commands only set the TOFF pin low during CLV mode. That pin will be at the high
level at all other times. Thus controlling the TOFF pin with microcontroller commands is only possible in
CLV mode.
Code
Command
RES = low
$EF
COMMAND INPUT NOISE REDUCTION MODE
$EE
CLEAR THE ABOVE MODE
q
Code
Command
RES = low
$04
DISC MOTOR START (accelerate)
$05
DISC MOTOR CLV (CLV)
$06
DISC MOTOR BRAKE (decelerate)
$07
DISC MOTOR STOP (stop)
q
Mode
CLV+
CLV–
Accelerate
High
Low
Decelerate
Low
High
CLV
Pulse output
Stop
Low