wm9712l Wolfson Microelectronics plc, wm9712l Datasheet - Page 25

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

Production Data
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AUDIO DACS
STEREO DAC
The WM9712L has a stereo sigma-delta DAC that achieves high quality audio playback at low power
consumption. Digital tone control, adaptive bass boost and 3-D enhancement functions operate on
the digital audio data before it is passed to the stereo DAC. (Contrary to the AC’97 specification, they
have no effect on analogue input signals or signals played through the auxiliary DAC. Nevertheless,
the ID2 and ID5 bits in the reset register, 00h, are set to ‘1’ to indicate that the WM9712L supports
tone control and bass boost.)
The DAC output has a PGA for volume control. The DAC sample rate can be controlled by writing to
a control register (see “Variable Rate Audio”). It is independent of the ADC sample rate. The left and
right DACs can be separately powered down using the PD13 and PD14 control bits, whereas the
PR1 bit disables both DACs (see “Power Management” section).
STEREO DAC VOLUME
The volume of the DAC output signal is controlled by a PGA (Programmable Gain Amplifier). It can
be mixed into the headphone, speaker and phone output paths (see “Audio Mixers”).
Table 11 Stereo DAC Volume Control
18h
DAC
Volume
5Ch
Additional
Functions
(1)
REGISTER
ADDRESS
15
14
13
12:8
4:0
15
7
BIT
D2H
D2S
D2P
DACL
VOL
DACR
VOL
AMUTE
AMEN
LABEL
1
1
1
01000
(0dB)
01000
(0dB)
0
0
DEFAULT
Mute DAC path to headphone mixer
1: Mute, 0: No mute (ON)
Mute DAC path to speaker mixer
1: Mute, 0: No mute (ON)
Mute DAC path to phone mixer
1: Mute, 0: No mute (ON)
Left DAC Volume
00000: +12dB
… (1.5dB steps)
11111: -34.5dB
Right DAC Volume
similar to DACLVOL
Read-only bit to indicate auto-muting
1: DAC auto-muted
0: DAC not muted
DAC Auto-Mute Enable
1: Automatically mutes analogue output of
stereo DAC if digital input is zero
0: Auto-mute OFF
DESCRIPTION
PD Rev 4.5 August 2006
WM9712L
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