92hd81 Integrated Device Technology, 92hd81 Datasheet - Page 21

• Manufacturer Part Number: 92hd81
• Description: Single Chip Pc Audio System
• Manufacturer: Integrated Device Technology

SINGLE CHIP PC AUDIO SYSTEM, CODEC+SPEAKER AMPLIFIER+CAPLESS HP+LDO
92HD81
SINGLE CHIP PC AUDIO SYSTEM, CODEC+SPEAKER AMPLIFIER+CAPLESS HP+LDO
2.11. Low-voltage HDA Signaling
2.12. Multi-channel capture
ther reduces power consumption on the digital supply by turning off GPIO drivers, and reduces ana-
log power consumption by turning off all analog circuitry except for reset circuits.
States D4/D5 are not entered until D3cold has been requested. Software can pre-program the D4 or
D5 state as a re-definition of how the part will behave when the D3cold power state is requested or
software may enter D3cold, then set the D4 or D5. The preferred method is to request D3cold, then
select D4 or D5 as desired.This will reduce the severity of pops encountered when entering D4 or
D5.
Both power states require a link reset or removal of DVDD to exit.
The CODEC may pop when using these verbs and transition times to an active state (D1 or D0 for
example) may take several seconds.
The Yangtze Series codec is compatible with either 1.5V or 3.3V HDA bus signaling; the voltage
selection is done dynamically based on the input voltage of DVDD_IO.
DVDD_IO is currently not a logic configuration pin, but rather provides the digital power supply to be
used for the HDA bus signals.
When in 1.5V mode, the Yangtze Series codec can correctly decode BITCLK, SYNC, RESET# and
SDO as they operate at 1.5V; additionally it will drive SDI and SDO at 1.5V. None of the GPIOs are
affected, as they always function at their nominal voltage (DVDD or AVDD).
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 this is done by assigning unique non zero Stream IDs to each converter. All capture
devices (ADCs 0 and 1) may 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”.
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92HD81
PC AUDIO
V 0.97 01/09