wm9712l Wolfson Microelectronics plc, wm9712l Datasheet - Page 32

• Manufacturer Part Number: wm9712l
• Description: Ac?97 Audio And Touchpanel Codec
• Manufacturer: Wolfson Microelectronics plc

WM9712L
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PHONE OUTPUT (MONOOUT)
THERMAL SENSOR
The MONOOUT output (pin 33) is intended for connection to the TX side of a wireless chipset. The
signal is generated in a dedicated mono mixer; it is not necessarily a mono mix of the stereo outputs
HPOUTL/R or LOUT2/ROUT2 (see “Audio Mixers” section).
The MONOOUT volume can be controlled by writing to register 06h. When MONOOUT is not used,
the output buffer can be disabled to save power (see “Power Management” section). The MONOOUT
pin remains at the same DC level (the reference voltage on the VREF pin), so that no click noise is
produced when muting or un-muting.
Table 18 MONOOUT Control
The speaker and headphone outputs can drive very large currents. To protect the WM9712L from
becoming too hot, a thermal sensor has been built in. If the chip temperature reaches approximately
150°C, and the ENT bit is set, the WM9712L deasserts GPIO bit 11 in register 54h, a virtual GPIO
that can be set up to generate an interrupt to the CPU (see “GPIO and Interrupt Control” section).
Table 19 Thermal Cutout Control
06h
MONOOUT
Volume
5Ch
54h
REGISTER
ADDRESS
REGISTER
ADDRESS
2
11
BIT
15
7
4:0
BIT
ENT
TI
LABEL
MUTE
ZC
MONOOUT
VOL
LABEL
0
1
DEFAULT
1
0
00000
(0dB)
DEFAULT
Enable thermal sensor
0: Disabled
1: Enabled
Thermal sensor (virtual GPIO)
1: Temperature below 150°C
0: Temperature above 150°C
See also “GPIO and Interrupt Control” section.
Mute MONOOUT
1: Mute
0: No Mute
Zero Cross Enable
0: Change gain immediately
1: Change gain only on zero crossings,
or after time-out
MONOOUT Volume
00000: 0dB (maximum)
00001: -1.5dB
… (1.5dB steps)
11111: -46.5dB
DESCRIPTION
DESCRIPTION
PD Rev 4.5 August 2006
Production Data
32