Rainbow Electronics MAX9867 - Manual (Page 42)

MAX9867
Ultra-Low Power Stereo Audio Codec
42 ______________________________________________________________________________________
Digital Microphone Input
The MAX9867 can accept audio from up to two digital
microphones. When using digital microphones, the left
analog microphone input is retasked as a digital micro-
phone input. The right analog microphone input is still
available to allow a combination of analog and digital
microphones to be used. Figure 6 shows the digital
microphone interface timing diagram. See Table 15.
Table 15. Digital Microphone Input Register
REGISTER B7 B6 B5 B4 B3 B2 B1 B0
REGISTER
ADDRESS
Microphone MICCLK DIGMICL DIGMICR 0 0 0 0 0x15
BITS FUNCTION
MICCLK
Digital Microphone Clock
00 = PCLK/8
01 = PCLK/6
10 = Reserved
11 = Reserved
Digital Left/Right Microphone Enable
DIGMICL DIGMICR Left ADC Input Right ADC Input
0 0 ADC input mixer ADC input mixer
0 1
Line input (left analog
microphone unavailable)
Right digital microphone
1 0 Left digital microphone ADC input mixer
1 1 Left digital microphone Right digital microphone
DIGMICL/DIGMICR
Note: The left analog microphone input is never available when DIGMICL or DIGMICR = 1.
DIGMICCLK
DIGMICDATA
t SU, MIC t HD, MIC t SU, MIC t HD, MIC
LEFT RIGHT LEFT RIGHT
1/f
MICCLK
Figure 6. Digital Microphone Timing Diagram