Production Data
WM8772EFT – 32 LEAD TQFP
POWERDOWN MODE AND ADC/DAC DISABLE
Setting the PDWN register bit immediately powers down the DAC’s on the WM8772EFT, overriding
the DACD powerdown bits control bits. All trace of the previous input samples are removed, but all
control register settings are preserved. When PDWN is cleared the digital filters will be reinitialised
REGISTER ADDRESS
0000010
BIT
LABEL
DEFAULT
DESCRIPTION
Power Down all DAC’s Select:
0: All DAC’s enabled
2
PDWN
0
Powerdown Control
1: All DAC’s disabled
The ADC and DACs may also be powered down individually by setting the ADCPD and DACPD
disable bits. Setting ADCD will disable the ADC and select a low power mode. The ADC digital filters
will be reset and will reinitialise when ADCPD is unset. Each Stereo DAC channel has a separate
disable DACPD[2:0]. Setting DACPD for a channel will disable the DACs and select a low power
mode. Resetting DACD will reinitialise the digital filters.
REGISTER ADDRESS
0001010
BIT
LABEL
DEFAULT
DESCRIPTION
ADC Disable:
0
ADCPD
0
Powerdown Control
0: Active
1: Disable
3:1 DACPD [2:0]
000
DAC Disable
DACPD [2:0]
000
DAC CHANNEL 1
Active
DAC CHANNEL 2
DAC CHANNEL 3
Active
Active
Active
001
DISABLE
Active
Active
010
DISABLE
DISABLE
Active
Active
011
DISABLE
Active
Active
100
DISABLE
DISABLE
DISABLE
DISABLE
101
DISABLE
Active
Active
110
DISABLE
DISABLE
111
DISABLE
MASTER POWERDOWN
This control bit powers down the references for the whole chop. Therefore for complete powerdown,
both the ADC and DACs should be powered down first before setting this bit.
REGISTER ADDRESS
0001010
BIT
LABEL
DEFAULT
DESCRIPTION
Master Power Down Bit:
0: Not powered down
1: Powered down
4
PWRDNALL
0
Interface Control
DAC MASTER MODE SELECT
Control bit DACMS selects between audio interface Master and Slave Modes. In Master mode
DACLRC and DACBCLK are outputs and are generated by the WM8772EFT. In Slave mode
DACCLRC, DACLRC and DACBCLK are inputs to WM8772EFT.
REGISTER ADDRESS
0001010
BIT
LABEL
DEFAULT
DESCRIPTION
5
DACMS
0
DAC Audio Interface
Master/Slave Mode Select:
Interface Control
0: Slave Mode
1: Master Mode
PD Rev 4.2 October 2005
63
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
