wm8982gefl-v Wolfson Microelectronics plc, wm8982gefl-v Datasheet - Page 44

• Manufacturer Part Number: wm8982gefl-v
• Description: Mono Codec With Speaker Driver And Video Buffer
• Manufacturer: Wolfson Microelectronics plc

WM8982
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The DAC output defaults to non-inverted. Setting DACPOL will invert the DAC output phase.
AUTOMUTE
The DAC has an automute function which applies an analogue mute when 1024 consecutive zeros
are detected. The mute is released as soon as a non-zero sample is detected. Automute can be
disabled using the AMUTE control bit.
DIGITAL HI-FI DAC VOLUME (GAIN) CONTROL
The signal volume from the Hi-Fi DAC can be controlled digitally. The gain and attenuation range is –
127dB to 0dB in 0.5dB steps. The level of attenuation for an eight-bit code X is given by:
0.5 × (X-255) dB for 1 ≤ X ≤ 255;
Table 28 DAC Digital Volume Control
Note: An additional gain of up to +12dB can be added using the gain block embedded in the
digital peak limiter circuit (see DAC OUTPUT LIMITER section).
DAC 5-BAND EQUALISER
A 5-band graphic equaliser function which can be used to change the output frequency levels to suit
the environment. This can be applied to the ADC or DAC path and is described in the 5-BAND
EQUALISER section for further details on this feature.
DAC DIGITAL OUTPUT LIMITER
The WM8982 has a digital output limiter function. The operation of this is shown in Figure 25. In this
diagram the upper graph shows the envelope of the input/output signals and the lower graph shows
the gain characteristic.
R11
DAC Digital
Volume
REGISTER
ADDRESS
7:0
8
BIT
DACVOL
[7:0]
DACVU
LABEL
MUTE for X = 0
11111111
( 0dB )
Not
latched
DEFAULT
DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
DAC volume does not update until a
1 is written to DACVU
PP, Rev 3.2, September 2008
DESCRIPTION
Pre-Production
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