92hd89c Integrated Device Technology, 92hd89c Datasheet - Page 23

• Manufacturer Part Number: 92hd89c
• Description: Six Channel Hd Audio Codec
• Manufacturer: Integrated Device Technology

92HD89C
Six channel HD Audio codec optimized for low power
©2009 INTEGRATED DEVICE TECHNOLOGY, INC.
IDT™ CONFIDENTIAL
2.13. Digital Microphone Support
The digital microphone interface permits connection of a digital microphone(s) to the CODEC via the
DMIC0 and DMIC_CLK 2-pin interface. The DMIC0 signal is an input that carries 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 widget that incorporates a boost amplifier. The
pin widget is 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.
[10:8]
[6:4]
[3:0]
[7:4]
[3:0]
SmplRateDiv
BitsPerSmpl
NmbrChan
Strm
Ch
Table 8: Mult-channel
23
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.
…
V 0.91 08/09
92HD89C