92hd75b Integrated Device Technology, 92hd75b Datasheet - Page 16

• Manufacturer Part Number: 92hd75b
• Description: Four Channel Hd Audio Codec
• Manufacturer: Integrated Device Technology

4-CHANNEL HD AUDIO CODECS OPTIMIZED FOR LOW POWER
92HD75B
4-CHANNEL HD AUDIO CODECS OPTIMIZED FOR LOW POWER
1.No DAC or ADC streams are active. Analog mixing and loop thru are supported.
2.VAG is kept active when ports are disabled or in D2/D3. Ports A, D, F and mono may be powered down using vendor specific
verbs.
3.VAG is always ramped up and down gradually, except in the case of a sudden power removal. VAG is active in D2/D3 but in
a low power state.
4. BITCLK must be active and both AVDD and DVDD must be available for Port Sense to operate.
5.Vendor specific bit for Ref Top controls VAG generator, Bandgap Reference, and Reference bias generator. Place part into
D3 and power down all ports (using vendor specific verbs) before powering down Ref Top.
6.Not active if BITCLK is not running (Controller in D3).
On
On
On
On
On
On
On
On
On
On
On
On
On
On
On
D0
1.4.10. Multi-channel capture
D1
Off
Off
Off
Off
Off
Off
On
On
On
On
On
On
On
On
On
The default power state for the Audio Function Group after reset is D3-default..
The capability to assign multiple “ADC Converters” to the same stream is supported to meet the
microphone array requirements of Vista and future operating systems. Single converter streams are
still supported and is done by assigning unique non zero Stream IDs to each converter. All capture
devices (ADCs 0 and 1) must be used to create a multi-channel input stream. There are no restric-
tions regarding digital microphones.
The ADC Converters can be associated with a single stream as long the sample rate and the bits per
sample are the same. The assignment of converter to channel is done using the “CnvtrID” widget
and is restricted to even values. The ADC converters will always put out a stereo sample and there-
fore require 2 channels per converter.
The stream will not be generated unless all entries for the targeted converters are set identically, and
the total number of assigned converter channels matches the value in the NmbrChan field. These
are listed the “Multi-Converter Stream Critical Entries.” table.
An example of a 4 Channel Steam with ADC0 supplying channels 0&1 and ADC1 supplying chan-
nels 2 & 3 is shown below. A 4 Channel stream can be created by assigning the same non-zero
stream id “Strm= N” to both ADC0 and ADC1. The sample rates must be set the same and the num-
ber of channels must be set to 4 channels “NmbrChan = 0011”.
D2
Off
Off
Off
Off
Off
Off
Off
Off
On
On
On
On
On
On
On
1
Low Drive2
Low Drive
Low Drive
Table 4. Power Managemen
On
On
Off
Off
Off
Off
Off
Off
Off
Off
On
On
D3
4
6
2
3
vendor specific
Programmable5
Programmable
16
Programmable
Programmable
Programmable
Programmable
-
-
-
-
-
-
-
-
-
5
92HD75B
Reference Bias generator
Reference Bandgap core
ADC Volume Control
Analog Clocks
VrefOut Pins
Input Boost
Port Sense
Function
HP Amps
VAG amp
Ref ADC
Lo Amp
AZ-Link
DAC
ADC
D2S
PC AUDIO
V 1.0 01-09