WM8711 Wolfson Microelectronics Ltd., WM8711 Datasheet - Page 22

• Manufacturer Part Number: WM8711
• Description: Internet Audio DAC With Integrated Headphone Driver
• Manufacturer: Wolfson Microelectronics Ltd.

WM8711
WOLFSON MICROELECTRONICS LTD
Table 10 Sample Rate Control
NORMAL MODE SAMPLE RATES
In normal mode MCLK is set up according to the desired sample rates of the DAC. For DAC
sampling rates of 8, 32, 48 or 96KHz, MCLK frequencies of either 12.288MHz (256Fs) or 18.432MHz
(384Fs) can be used. DAC sampling rates of 8, 44.1 or 88.2KHz from MCLK frequencies of either
11.2896MHz (256Fs) or 16.9344MHz (384Fs) can be used.
The table below should be used to set up the device to work with the various sample rate
combinations. Refer to Digital Filter Characteristics section for an explanation of the different filter
types.
Table 11 Normal Mode Sample Rate Look-up Table
Notes:
1.
2.
The BOSR bit represents the base over-sampling rate. This is the rate that the WM8711 digital signal
processing is carried out at. In Normal mode, with BOSR = 0, the base over-sampling rate is at
256Fs, with BOSR = 1, the base over-sampling rate is at 384Fs. This can be used to determine the
actual audio data rate required by the DAC.
0001000
Sampling
Control
SAMPLING
REGISTER
ADDRESS
8k not exact, actual = 8.018kHz
All other combinations of BOSR and SR[3:0] that are not in the truth table are invalid
(Note 1)
RATE
DAC
KHz
44.1
88.2
48
32
96
8
8
0
1
5:2
BIT
FREQUENCY
11.2896
16.9344
11.2896
16.9344
11.2896
16.9344
12.288
18.432
12.288
18.432
12.288
18.432
12.288
18.432
MCLK
MHz
USB/
NORMAL
BOSR
SR[3:0]
LABEL
BOSR
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
0000
DEFAULT
SR3
REGISTER SETTINGS
0
0
0
0
0
0
0
0
1
1
1
1
1
1
SAMPLE
RATE
SR2
Mode Select
1 = USB mode (250/272fs)
0 = Normal mode (256/384fs)
Base Over-Sampling Rate
USB Mode
0 = 250fs
1 = 272fs
DAC sample rate control;
See USB Mode and Normal Mode
Sample Rate sections for operation
0
0
0
0
1
1
1
1
0
0
0
0
1
1
SR1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
DESCRIPTION
PP Rev 1.2 November 2000
SR0
Normal Mode
0 = 256fs
1 = 384fs
0
0
1
1
0
0
1
1
0
0
1
1
1
1
Product Preview
DIGITAL
FILTER
TYPE
1
1
1
2
1
1
2
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