AD1985

Rev. A | Page 33 of 48

EQ Control Register (Index 0x60)

Reg.Num.

Name

D15

D14 D13 D12 D11 D10 D9 D8 D7

D6

D5

D4

D3

D2

D1

D0

Default

0x60

EQ Control

EQM X

X

X

X

X

X

X

SYM CHS BCA5 BCA4 BCA3 BCA2 BCA1 BCA0 0x8080

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

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]

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

CHS

Channel Select. CHS = 0: Selects left channel coefficients data block. CHS = 1: Selects right channel coefficients data block.

SYM

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.)

EQM

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.