µPD9930
(3) Input/output amplifier control register (AMPCR)
This is a 5-bit register for power up/down control of each input/output amplifier (not including receiver amplifier
2), and for ringer output ON/OFF control.
Remark For information on power up/down control of receiver amplifier 2, refer to 4.1.1 Voice Send Analog Gain/
Receiver Amplifier 2 Control Register (TXGCR).
Figure 2-6 Input/Output Amplifier Control Register
Register address
AMPCR
D2
D7
0
D6
0
D5
0
D4
D3
D1
D0
MICPDB XAUXPDB REC1PDB RAUXPDB RINGPDB
MICPDB Microphone amplifier power control
Power down
Power up
0
1
XAUXPDB Accessory input amplifier power control
Power down
Power up
0
1
REC1PDB Receiver amplifier 1 power control
Power down
Power up
0
1
RAUXPDB Accessory output amplifier power control
Power down
Power up
0
1
RINGPDB Ringer output control
Sets output at low level.
Output enable
0
1
Remarks 1. In the stand-by mode, all amplifiers enter the power down state regardless of input/output control register
settings. However, register contents are held unless reset or written, so when the stand-by mode is
cleared by power up command, the command prior to the stand-by mode is resumed.
2. The microphone and accessory amplifiers cannot enter the power up (D4 = D3 = "1") state at the same
time.
14
NEC [ NEC ]
