wm8940gefl-v Wolfson Microelectronics plc, wm8940gefl-v Datasheet - Page 58

• Manufacturer Part Number: wm8940gefl-v
• Description: Mono Codec With Speaker Driver
• Manufacturer: Wolfson Microelectronics plc

WM8940
w
COMPANDING
The PLL performs best when f
are shown in Table 49.
Table 49 PLL Frequency Examples
Table 50 Companding Control
(MHz)
The WM8940 supports A-law and µ-law companding on both transmit (ADC) and receive (DAC)
sides. Companding can be enabled on the DAC or ADC audio interfaces by writing the appropriate
value to the DAC_COMP or ADC_COMP register bits respectively. If packed mode companding is
desired the WL8 register bit is available. It will override the normal audio interface WL bits to give an
8-bit word length. Refer to Table 43 Audio Interface Control for setting the output word length.
19.68
19.68
MCLK
14.4
14.4
19.2
19.2
19.8
19.8
R5
Companding
control
12
12
13
13
24
24
26
26
27
27
REGISTER
ADDRESS
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
11.2896
12.2880
DESIRED
OUTPUT
(MHz)
6
4:3
2:1
0
BIT
DAC_LOOPBACK
DAC_COMP
ADC_COMP
ADC_LOOPBACK
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
90.3168
98.3040
(MHz)
F2
LABEL
2
is around 90MHz. Its stability peaks at N=8. Some example settings
PRESCALE
DIVIDE
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
0
0
0
0
DEFAULT
POSTSCALE
(MCLKDIV)
DIVIDE
Digital loopback function
0=No DAC loopback
1=Loopback enabled, DAC audio interface
output is fed directly into ADC audio
interface input.
DAC decompanding
00=off
01=reserved
10=µ-law
11=A-law
ADC companding
00=off
01=reserved
10=µ-law
11=A-law
Digital loopback function
0=No ADC loopback
1=Loopback enabled, ADC data output is
fed directly into DAC data input.
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
6.947446
7.561846
6.826667
9.178537
9.990243
9.122909
9.929697
6.947446
7.561846
6.690133
7.281778
7.5264
7.5264
8.192
6.272
9.408
10.24
8.192
DESCRIPTION
R
PD, Rev 4.2, April 2008
(Hex)
A
7
8
6
7
6
6
9
9
9
9
9
7
8
6
7
6
7
N
Production Data
BOAC93
45A1CA
D3A06E
F28BD4
3D70A3
2DB492
FD809F
EE009E
F28BD4
86C226
8FD525
1F76F8
86C226
8FD525
3126E9
6872B0
3126E9
482296
(Hex)
K
58