AD1985 Analog Devices, AD1985 Datasheet - Page 33

• Manufacturer Part Number: AD1985
• Description: AC'97 2.3 Soundmax Codec W/jack Sensing
• Manufacturer: Analog Devices

EQ Control Register (Index 0x60)
Reg.Num.
0x60
Register 0x60 is a read/write register that controls equalizer
function and data setup. The register also contains the Biquad
and Coefficient Address pointer, which is used in conjunction
with the EQ Data Register (0x78) to set up the equalizer
coefficients. The reset default disables the equalizer function
BCA[5:0]
CHS
SYM
EQM
Name
EQ CTRL
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
Channel Select. CHS = 0: Selects left channel coefficients data block. CHS = 1: Selects right channel coefficients data block.
Symmetry. When set to 1 this bit indicates that the left and right channel coefficients are equal. This shortens the coefficient setup
sequence since only the left channel coefficients need to be addressed and set up. (The right channel coefficients are simultaneously
copied into memory.)
Equalizer Mute. When set to 1, this bit disables the equalizer function (allows all data to pass through). The reset default sets this bit to 1,
disabling the equalizer function until the biquad coefficients can be properly set.
Biquad and Coefficient Address pointer:
D15 D14 D13 D12 D11 D10 D9 D8 D7
EQM X
X
X
X
X
Rev. 0 | Page 33 of 48
X
X
SYM CHS BCA5 BCA4 BCA3 BCA2 BCA1 BCA0 0x8080
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.
D6
D5
D4
D3
D2
D1
D0
AD1985
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