WM9714L_06 WOLFSON [Wolfson Microelectronics plc], WM9714L_06 Datasheet - Page 30

• Manufacturer Part Number: WM9714L_06
• Description: AC 97 Audio CODEC
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM9714L
AUDIO DACS
STEREO DAC
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The WM9714L 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 WM9714L 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.
When not in use the DACs can be separately powered down using the Powerdown register bits
DACL and DACR (register 3Ch, bits [7:6]).
STEREO DAC VOLUME
The volume of the DAC output signal is controlled by a PGA (Programmable Gain Amplifier). Each
DAC can be mixed into the headphone, speaker and mono mixer paths (see “Audio Mixers”)
controlled by register 0Ch.
Each DAC-to-mixer path has an independent mute bit. When all DAC-to-mixer paths are muted the
DAC PGA is muted automatically.
When not in use the DAC PGAs can be powered down using the Powerdown register bits DACL and
DACR (register 3Ch, bits [7:6]).
Table 16 Stereo DAC Volume Control
0Ch
DAC
Volume
5Ch
Additional
Functions
(2)
REGISTER
ADDRESS
15
14
13
12:8
4:0
15
7
BIT
D2H
D2S
D2M
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 mono 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
PP Rev 3.0 June 2006
Pre-Production
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