Pre-Production
WM8850
Regardless of the type of input, the sample rate and word length of the data captured by the MIC1
node is set using the Stream Format Verb. Table 15 below shows the required settings for Base, Mult
and Div as part of the Stream Format Verb to obtain the required sample rate.
When a digital microphone is being used, the DMICCLK output frequency will be set according to the
Stream Format Verb. See “Digital Microphone Record” for details of the DMICCLK frequency.
SAMPLE RATE
8kHz
BASE
0h
MULT[2:0]
DIV[2:0]
5h
0h
0h
0h
0h
1h
0h
0h
11.025kHz
16kHz
1h
3h
0h
2h
22.05kHz
32kHz
1h
1h
0h
2h
44.1kHz
48kHz
1h
0h
0h
0h
Table 15 MIC1 Supported Sample Rate Settings
Note: Other settings of Base, Mult and Div are reserved and should not be set.
The MIC1 output data is by default set to provide the captured waveform from the left channel in
Channel 0, and the right channel in Channel 1. It is possible to adjust this mapping using the vendor-
specific Channel Copy Verb.
SET VERB
BIT
BITFIELD
NAME
DEFAULT
DESCRIPTION
7B1h
1
CHAN1_
SEL
1
Channel 1 (right) Mapping Control:
0 = Channel 1 takes data from left audio
channel
1 = Channel 1 takes data from right audio
channel
0
CHAN0_
SEL
0
Channel 0 (left) Mapping Control:
0 = Channel 0 takes data from left audio
channel
1 = Channel 0 takes data from right audio
channel
PP, April 2011, Rev 3.2
47
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
