wm8770 Wolfson Microelectronics plc, wm8770 Datasheet - Page 27

• Manufacturer Part Number: wm8770
• Description: 24-bit, 192khz 8-channel Codec With Volume Control
• Manufacturer: Wolfson Microelectronics plc

Production Data
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MASTER MODE ADCLRC/DACLRC FREQUENCY SELECT
In Master mode the WM8770 generates ADCLRC, DACLRC and BCLK. These clocks are derived
from master clock and the ratio of MCLK to ADCLRC and DACLRC are set by ADCRATE and
DACRATE.
ADC OVERSAMPLING RATE SELECT
For ADC operation at 96kHz it is recommended that the user set the ADCOSR bit. This changes the
ADC signal processing oversample rate to 64fs.
MUTE MODES
The WM8770 has individual mutes for each of the four DAC channels. Setting MUTE for a channel
will apply a ‘soft’ mute to the input of the digital filters of the channel muted. DMUTE[0] mutes DAC
channel 1, DMUTE[1] mutes DAC channel 2, DMUTE[2] mutes DAC channel 3 & DMUTE[3] mutes
DAC channel 4.
Setting the MUTEALL register bit will apply a 'soft' mute to the input of all the DAC digital filters:
10111
Interface Control
10111
ADCLRC and DACLRC
Frequency Select
10111
ADC Oversampling
Rate
10100
Mute Control
10100
Mute Control
REGISTER ADDRESS
REGISTER ADDRESS
REGISTER ADDRESS
REGISTER ADDRESS
REGISTER ADDRESS
BIT
BIT
2:0
6:4
BIT
BIT
3:0
BIT
8
3
4
ADCRATE[2:0]
DACRATE[2:0]
DMUTE[3:0]
MUTEALL
ADCOSR
LABEL
LABEL
LABEL
LABEL
LABEL
MS
DEFAULT
DEFAULT
DEFAULT
DEFAULT
DEFAULT
010
010
0
0
0
0
Audio Interface Master/Slave
Mode select:
Master Mode MCLK:ADCLRC
ratio select:
Master Mode MCLK:DACLRC
ratio select:
ADC oversampling rate select
DAC Soft Mute select
Soft Mute select
0 : Slave Mode
1: Master Mode
0 : Normal Operation
1: Soft mute enabled
0 : Normal Operation
1: Soft mute all channels
010: 256fs
011: 384fs
100: 512fs
101: 768fs
000: 128fs
001: 192fs
010: 256fs
011: 384fs
100: 512fs
101: 768fs
0: 128x oversampling
1: 64x oversampling
DESCRIPTION
DESCRIPTION
DESCRIPTION
DESCRIPTION
DESCRIPTION
PD Rev 4.2 March 2008
WM8770
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