Audio Codec (AC)
User Manual All information provided in this document is subject to legal disclaimers. © REALTEK 2019. All rights reserved.
337
CLK
DATA
Data (R)
Data (R)
Data (R)
Data (L)
Data (L)
Data (L)
Fig 17-11 Stereo PDM format
Besides connecting digital mic-phone with DMIC_CLK/DMIC_DATA, you can also connect it with external I
2
S interface directly (see Fig 17-12).
Set I
2
S bit clock to 64*Fs, that is 1MHz if Fs=16kHz.
Need to implement decimation filter by software. It consumes about 4k cycles per 1024 bits on Cortex-M4, which means the
computation complexity is about 4 MCPS if a 1MHz PDM clock is used.
AmebaD
I2S_BCLK
0.1uF
VDD
Digital MIC
CLOCK
GND
MICBIAS
I2S_DI
DATA
L/R
External I2S
Fig 17-12 I
2
S acting as PDM
17.6
Registers
17.6.1
Analog Part
17.6.1.1
0x00
Address
Bit
Name
Access
Reset
Description
0x00
[0]
DAC_ADDACK_POW
R/W
1'b0
AD/DA clock power down control
[1]
DAC_CKXEN
R/W
1'b0
DAC chopper clock enable control
1’b0: Disable
1’b1: Enable
[2]
DAC_CKXSEL
R/W
1'b0
DAC chopper clock selection
1’b0: ckx2/4
1’b1: ckx2/8
[3]
DAC_L_POW
R/W
1'b0
DAC left channel power down control
1’b0: Power down
1’b1: Power on
[4]
DAC_R_POW
R/W
1'b0
DAC right channel power down control
1’b0: Power down
1’b1: Power on
[6:5]
DPRAMP_CSEL
R/W
2'b00
Depop C size selection
2’b00: 1x
2’b01: 2x
Realtek confidential files
The document authorized to
SZ99iot
2019-05-15 10:08:03