WM8711BL Wolfson Microelectronics, WM8711BL Datasheet - Page 29

• Manufacturer Part Number: WM8711BL
• Description: Ultra-Small Audio DAC
• Manufacturer: Wolfson Microelectronics

Production Data
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128/192FS NORMAL MODE
The Normal Mode sample rates are designed for standard 256fs and 384fs MCLK rates. However the
WM8711BL is also capable of being clocked from a 128/192fs MCLK for application over limited
sampling rates as shown in the table below.
Table 13 128/192fs Normal Mode Sample Rate Look-up Table
512/768FS NORMAL MODE
512fs and 768fs MCLK rates can be accommodated by using the CLKIDIV2 bit. The core clock to the
DSP will be divided by 2 so an external 512/768 MCLK will become 256/384fs internally and the
device otherwise operates as in Table 9 but with MCLK at twice the specified rate.
USB MODE SAMPLE RATES
In USB mode the MCLK input is 12MHz only.
Table 14 USB Mode Sample Rate Look-Up Table
Notes:
1.
2.
3.
4.
The BOSR bit represents the base over-sampling rate. This is the rate that the WM8711BL digital
signal processing is carried out at and the sampling rate will always be a sub-multiple of this. In USB
mode, with BOSR = 0, the base over-sampling rate is defined at 250Fs, with BOSR = 1, the base
over-sampling rate is defined at 272Fs. This can be used to determine the actual audio sampling rate
required by the DAC.
SAMPLING RATE
SAMPLING RATE
8k not exact, actual = 8.021kHz
44.1k not exact, actual = 44.118kHz
88.1k not exact, actual = 88.235kHz
All other combinations of BOSR and SR[3:0] that are not in the truth table are invalid
(Note 2)
(Note 1)
(Note 3)
DAC
DAC
44.1
44.1
88.2
kHz
kHz
48
48
32
96
8
8
FREQUENCY
FREQUENCY
5.6448
8.4672
12.000
12.000
12.000
12.000
12.000
12.000
12.000
MCLK
MCLK
6.144
9.216
MHz
MHz
BOSR
BOSR
0
1
0
1
0
1
0
1
0
0
1
SR3
SR3
REGISTER SETTINGS
REGISTER SETTINGS
0
0
1
1
0
1
0
1
0
0
1
SAMPLE
SAMPLE
RATE
RATE
SR2
SR2
1
1
1
1
0
0
0
0
1
1
1
SR1
SR1
1
1
1
1
0
0
0
0
1
1
1
PD, Rev 4.1, April 2007
SR0
SR0
1
1
1
1
0
0
1
1
0
1
1
WM8711BL
DIGITAL
DIGITAL
FILTER
FILTER
TYPE
TYPE
2
2
0
1
0
1
0
3
2
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