WM8980CGEFL/RV WOLFSON [Wolfson Microelectronics plc], WM8980CGEFL/RV Datasheet - Page 48

• Manufacturer Part Number: WM8980CGEFL/RV
• Description: Stereo CODEC with Speaker Driver and Video Buffer
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM8980
Figure 24 DAC Digital Filter Path
w
DIGITAL PLAYBACK (DAC) PATH
Table 27 DAC Enable Control
Table 28 DAC Control Register
The analogue outputs from the DACs can then be mixed with the aux analogue inputs and the ADC
analogue inputs. The mix is fed to the output drivers for headphone (LOUT1/ROUT1), speaker
(LOUT2/ROUT2) or line (OUT3/OUT4). OUT3 and OUT4 have additional mixers which allow them
to output different signals to the headphone and speaker outputs.
Digital data is passed to the WM8980 via the flexible audio interface and is then passed through a
variety of advanced digital filters (as shown in Figure 24) to the hi-fi DACs. The DACs are enabled by
the DACENL/R register bits.
The WM8980 also has a Soft Mute function, which, when enabled, gradually attenuates the volume
of the digital signal to zero. When disabled, the gain will ramp back up to the digital gain setting. This
function is enabled by default. To play back an audio signal, this function must first be disabled by
setting the SOFTMUTE bit to zero.
The digital audio data is converted to oversampled bit streams in the on-chip, true 24-bit digital
interpolation filters. The bitstream data enters the multi-bit, sigma-delta DACs, which convert it to a
high quality analogue audio signal. The multi-bit DAC architecture reduces high frequency noise and
sensitivity to clock jitter. It also uses a Dynamic Element Matching technique for high linearity and low
distortion.
R10
DAC Control
R3
Power
Management 3
REGISTER
ADDRESS
REGISTER
ADDRESS
BIT
0
1
0
1
2
3
6
BIT
DACPOLL
DACPOLR
AMUTE
DACOSR128
SOFTMUTE
DACENL
DACENR
LABEL
LABEL
0
0
DEFAULT
0
0
0
0
0
DEFAULT
Left channel DAC enable
0 = DAC disabled
1 = DAC enabled
Right channel DAC enable
0 = DAC disabled
1 = DAC enabled
Left DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
Right DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
Automute enable
0 = Amute disabled
1 = Amute enabled
DAC oversampling rate select:
0=64x (lowest power)
1=128x (best SNR)
Softmute enable:
0=Enabled
1=Disabled
DESCRIPTION
DESCRIPTION
PP, Rev 3.8, May 2012
Pre-Production
48