92HD91 Datasheet, PDF (21/298 Pages) Integrated Device Technology – SINGLE CHIP PC AUDIO SYSTEM

92HD91
SINGLE CHIP PC AUDIO SYSTEM, CODEC+SPEAKER AMPLIFIER+CAPLESS HP+LDO
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 so are actually D3cold options rather
than true, independent, power states. 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 before performing the power state get command. 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.
2.12. Low-voltage HDA Signaling
The codec is compatible with either 1.5V or 3.3V HDA bus signaling; in the 48QFN package the volt-
age 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 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).
2.13. Multi-channel capture
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”.
IDT™ CONFIDENTIAL
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92HD91