92HD81 Datasheet, PDF (22/279 Pages) Integrated Device Technology – SINGLE CHIP PC AUDIO SYSTEM

92HD81
SINGLE CHIP PC AUDIO SYSTEM, CODEC+SPEAKER AMPLIFIER+CAPLESS HP+LDO
[10:8]
[6:4]
[3:0]
[7:4]
[3:0]
SmplRateDiv
BitsPerSmpl
NmbrChan
Strm
Ch
Sample Base Rate Divisor
000= Divide by 1
001= Divide by 2 (not supported)
010= Divide by 3 (not supported)
011= Divide by 4 (not supported)
100= Divide by 5 (not supported)
101= Divide by 6 (not supported)
110= Divide by 7 (not supported)
111= Divide by 8 (not supported)
Bits per Sample
000= 8 bits (not supported)
001= 16 bits
010= 20 bits
011= 24 bits
100-111= Reserved
Number of Channels
Number of channels for this stream in each “sample
block” of the “packets” in each “frame” on the link.
0000=1 channel (not supported)
0001 = 2 channels
…
1111= 16 channels.
Software-programmable integer representing link
stream ID used by the converter widget. By conven-
tion stream 0 is reserved as unused.
Integer representing lowest channel used by con-
verter.
0 and 2 are valid Entries
If assigned to the same stream, one ADC must be
assigned a value of 0 and the other ADC assigned a
value of 2.
Table 7: Mult-channel
2.13. Digital Microphone Support
The digital microphone interface permits connection of a digital microphone(s) to the CODEC via the
DMIC0, DMIC1, and DMIC_CLK 3-pin interface. The DMIC0 and DMIC1 signals are inputs that carry
individual channels of digital microphone data to the ADC. In the event that a single microphone is
used, the data is ported to both ADC channels. This mode is selected using a vendor specific verb
and the left time slot is copied to the ADC left and right inputs.
The DMIC_CLK output is controllable from 4.704Mhz, 3.528Mhz, 2.352Mhz, 1.176Mhz and is syn-
chronous to the internal master clock. The default frequency is 2.352Mhz.
The two DMIC data inputs are reported as two stereo input pin widgets that incorporate a boost
amplifier. The pin widgets are shown connected to the ADCs through the same multiplexors as the
analog ports. Although the internal implementation is different between the analog ports and the dig-
ital microphones, the functionality is the same. In most cases, the default values for the DMIC clock
rate and data sample phase will be appropriate and an audio driver will be able to configure and use
the digital microphones exactly like an analog microphone.
To conserve power, the analog portion of the ADC will be turned off if the D-mic input is selected.
When switching from the digital microphone to an analog input to the ADC, the analog portion of the
IDT CONFIDENTIAL
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©2009 INTEGRATED DEVICE TECHNOLOGY, INC.
V 0.995 01/11
92HD81