92HD87 Datasheet, PDF (18/204 Pages) Integrated Device Technology – SINGLE CHIP PC AUDIO SYSTEM

92HD87
SINGLE CHIP PC AUDIO SYSTEM, CODEC+STEREO SPEAKER AMPLIFIER+CAPLESS HP+LDO
[6:4]
BitsPerSmpl
Bits per Sample
000= 8 bits (not supported)
001= 16 bits
010= 20 bits
011= 24 bits
100-111= Reserved
[3:0]
NmbrChan
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.
[7:4]
Strm
Software-programmable integer representing link
stream ID used by the converter widget. By conven-
tion stream 0 is reserved as unused.
[3:0]
Ch
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 5: Mult-channel
2.12. Digital Microphone Support
The digital microphone interface permits connection of a digital microphone(s) to the CODEC via the
DMIC0, and DMIC_CLK 3-pin interface. The DMIC0 signal is an input 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 DMIC data input is reported as a 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 digital micro-
phones, 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 digi-
tal 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
ADC will be brought back to a full power state and allowed to stabilize before switching from the dig-
ital microphone to the analog input. This should take less than 10mS.
DMIC pin widgets support port presence detect directly using SENSE-B input.
IDT CONFIDENTIAL
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©2009 INTEGRATED DEVICE TECHNOLOGY, INC.
V 0.995 01/11
92HD87