AD1980 Analog Devices, AD1980 Datasheet - Page 27

• Manufacturer Part Number: AD1980
• Description: AD1980 AC'97 SoundMAX® Codec W/spdif W/eq
• Manufacturer: Analog Devices

MBG[1:0]
VREFD
VREFH
SRU
LOSEL
2CMIC
SPRD
REV. 0
Reg
No. Name D15
76th Misc
Control
Bits
DACZ AC97NC MSPLT LODIS CLDIS HPSEL DMIX1 DMIX0 SPRD 2CMIC LOSEL SRU VREFH VREFD MBG1MBG0 0000h
MIC Boost Gain Select Register.
LINE_OUT Amplifiers Input Select. This bit allows the LINE_OUT output amplifiers to be driven by the mixer
2-Channel MIC Select. This bit enables simultaneous recording from MIC1 and MIC2 inputs, using a stereo
SPREAD Enable. This bit enables spreading of 2-channel media to all six output channels. This function is imple-
These two bits allow changing the MIC preamp gain from the nominal 20 dB gain. Both MIC1/MIC2 and MIC2
preamps will be set to the same selected gain.
Note that this gain takes effect only while Bit D6 (M20) on the MIC volume register (0Eh) is set to 1; otherwise the
MIC boost block has a gain of 0 dB.
00 = 20 dB gain (reset default)
01 = 10 dB gain
10 = 30 dB gain
11 = reserved
V
Note that this bit overrides the VREFH bit selection (see below).
0 = V
1 = V
V
0 = V
1 = V
Sample Rate Unlock. Controls DAC sample rate locking.
0 = All DAC Sample Rates are locked to the front sample rate (reset default).
1 = DAC sample rates can be set independently for front, surround, and LFE.
or the surround DACs. The main purpose for this is to allow swapping of the front and surround channels to make
better use of the SURR/HP_OUT output amplifiers. This bit should normally be used in tandem with the HPSEL
bit (see below).
0 = LINE_OUT amplifiers are driven by the mixer outputs (reset default).
1 = LINE_OUT amplifiers are driven by the surround DAC outputs.
microphone array. Note that this register works in conjunction with the MS bit in Register 20h.
0 = MIC1 or MIC2 (determined by MS bit) is routed to the record selector’s left and right MIC channels as well
as to the mixer (reset default).
1 = MIC1 is routed to the record selector’s left MIC channel and MIC2 is routed to the record selector’s right
MIC channel. Note that in this mode, the MS bit should be set low and MIC1 can still be enabled into the mixer.
mented in the analog section by using the output selector controls line for the center/LFE, surround, and Line_out
output channels. Note that the Jack Sense pins can also be set up to control (gate) this function, depending on the
JSSPRD bit (see Register 72h).
0 = No spreading occurs unless activated by the Jack Senses and JSSPRD bits (reset default).
1 = The SPRD selector drives the center and LFE outputs from the MONO_OUT, the HPSEL selector drives the
SURR/HP_OUT outputs from the mixer outputs, and the LOSEL selector drives the LINE_OUT outputs also
from the mixer outputs.
Note that the SPRD bit overrides the current output selector control lines set up by bits LOSEL and HPSEL as
follows: LOSEL = 0 and HPSEL = 1.
D14
REFOUT
REFOUT
REFOUT
REFOUT
REFOUT
REFOUT
High. Changes V
Disable. Disables V
D13
pin is driven by the internal reference (reset default).
pin is placed into High Z out mode.
pin is set to 2.25 V output (reset default).
pin is set to 3.70 V output.
D12
Miscellaneous Control Bit Register (Index 76h)
D11
REFOUT
REFOUT
D10
from 2.25 V to 3.70 V for PC2001 compliant MIC bias applications.
, placing it into High Z out mode.
D9
–27–
D8
D7
D6
D5
D4
D3
D2
D1
AD1980
D0
De-
fault