AD1981A Analog Devices, AD1981A Datasheet - Page 17

• Manufacturer Part Number: AD1981A
• Description: AD1981A AC'97 Soundmax Codec
• Manufacturer: Analog Devices

The reset default disables the equalizer function until the coefficients can be properly set up by the software and sets the Symmetry
Bit to allow equal coefficients for left and right channels.
BCA[5,0]
Reg. Num. Name
Register 60h is a read/write register that controls the equalizer functionality and data setup. The register also contains the biquad and coefficient address pointer,
which is used in conjunction with the EQ data register (78h) to set up the equalizer coefficients.
60h
EQCTRL EQM MAD LBEN X
Biquad and Coefficient Address Pointer:
biquad 0 coef a0 BCA[5,0] = 011011
biquad 0 coef a1 BCA[5,0] = 011010
biquad 0 coef a2 BCA[5,0] = 011001
biquad 0 coef b1 BCA[5,0] = 011101
biquad 0 coef b2 BCA[5,0] = 011100
biquad 1 coef a0 BCA[5,0] = 100000
biquad 1 coef a1 BCA[5,0] = 011111
biquad 1 coef a2 BCA[5,0] = 011110
biquad 1 coef b1 BCA[5,0] = 100010
biquad 1 coef b2 BCA[5,0] = 100001
biquad 2 coef a0 BCA[5,0] = 100101
biquad 2 coef a1 BCA[5,0] = 100100
biquad 2 coef a2 BCA[5,0] = 100011
biquad 2 coef b1 BCA[5,0] = 100111
biquad 2 coef b2 BCA[5,0] = 100110
biquad 3 coef a0 BCA[5,0] = 101010
biquad 3 coef a1 BCA[5,0] = 101001
biquad 3 coef a2 BCA[5,0] = 101000
biquad 3 coef b1 BCA[5,0] = 101100
biquad 3 coef b2 BCA[5,0] = 101011
biquad 4 coef a0 BCA[5,0] = 101111
biquad 4 coef a1 BCA[5,0] = 101110
biquad 4 coef a2 BCA[5,0] = 101101
biquad 4 coef b1 BCA[5,0] = 110001
biquad 4 coef b2 BCA[5,0] = 110000
biquad 5 coef a0 BCA[5,0] = 110100
biquad 5 coef a1 BCA[5,0] = 110011
biquad 5 coef a2 BCA[5,0] = 110010
biquad 5 coef b1 BCA[5,0] = 110110
biquad 5 coef b2 BCA[5,0] = 110101
biquad 6 coef a0 BCA[5,0] = 111001
biquad 6 coef a1 BCA[5,0] = 111000
biquad 6 coef a2 BCA[5,0] = 110111
biquad 6 coef b1 BCA[5,0] = 111011
biquad 6 coef b2 BCA[5,0] = 111010
D15
D14
D13 D12 D11 D10 D9 D8 D7
X
EQ Control Register (Index 60h)
X
X
X
X SYM CHS BCA5 BCA4 BCA3 BCA2 BCA1 BCA0 8080h
D6
D5
D4
D3
D2
D1
AD1981A
D0
Default