wm8940gefl-v Wolfson Microelectronics plc, wm8940gefl-v Datasheet - Page 26

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

WM8940
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Table 16 Notch Filter 1 Function
Table 17 Notch Filter 2 Function
Table 18 Notch Filter 3 Function
The notch filter coefficients must be entered using a sign / magnitude notation.
The MSB of the 14-bit register word (NFx_Ax[13]) is reserved for the sign part, leaving the 13
remaining bits for the magnitude part.
The notch filter coefficients are calculated as follows:
R18
Notch Filter 1A
R19
Notch Filter 1B
R20
Notch Filter 2A
R21
Notch Filter 2B
R22
Notch Filter 3A
R23
Notch Filter 3B
REGISTER
REGISTER
REGISTER
ADDRESS
ADDRESS
ADDRESS
15
14
13:0
15
13:0
15
14
13:0
15
13:0
15
14
13:0
15
14
13:0
BIT
BIT
BIT
NF1_UP
NF1_EN
NF1_A0
NF1_UP
NF1_A1
NF2_UP
NF2_EN
NF2_A0
NF2_UP
NF2_A1
NF3_UP
NF3_EN
NF3_A0
NF3_UP
NF3_LP
NF3_A1
LABEL
LABEL
LABEL
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
DEFAULT
DEFAULT
DEFAULT
Notch filter 1 update. The notch filter 1
values used internally only update when
one of the NFU bits is set high.
Notch Filter 1 enable.
0=Disabled
1=Enabled
Notch Filter 1 a0 coefficient
Notch filter 1 update. The notch filter 1
values used internally only update when
one of the NFU bits is set high.
Notch Filter 1 a1 coefficient
Notch filter 2 update. The notch filter 2
values used internally only update when
one of the NFU bits is set high.
Notch Filter 2 enable.
0=Disabled
1=Enabled
Notch Filter 2 a0 coefficient
Notch filter 2 update. The notch filter 2
values used internally only update when
one of the NFU bits is set high.
Notch Filter 2 a1 coefficient
Notch filter 3 update. The notch filter 3
values used internally only update when
one of the NFU bits is set high.
Notch Filter 3 enable.
0=Disabled
1=Enabled
Notch Filter 3 a0 coefficient
Notch filter 3 update. The notch filter 3
values used internally only update when
one of the NFU bits is set high.
Notch Filter 3 mode select
0 = Notch Filter mode
1 = Low Pass Filter mode
Notch Filter 3 a1 coefficient
DESCRIPTION
DESCRIPTION
DESCRIPTION
PD, Rev 4.2, April 2008
Production Data
26