Production Data
WM9715L
AUDIO DACS
STEREO DAC
The WM9715L 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 WM9715L 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”).
REGISTER
ADDRESS
BIT
15
LABEL
D2H
DEFAULT
DESCRIPTION
18h
1
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
DAC
Volume
14
D2S
D2P
1
1
13
12:8
DACL
VOL
01000
(0dB)
00000: +12dB
… (1.5dB steps)
11111: -34.5dB
4:0
15
DACR
VOL
01000
(0dB)
0
Right DAC Volume
similar to DACLVOL
5Ch
AMUTE
Read-only bit to indicate auto-muting
1: DAC auto-muted
Additional
Functions
(1)
0: DAC not muted
7
AMEN
0
DAC Auto-Mute Enable
1: Automatically mutes analogue output of
stereo DAC if digital input is zero
0: Auto-mute OFF
Table 11 Stereo DAC Volume Control
PD Rev 4.0 December 2007
25
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