ISD94100 Series Technical Reference Manual
Sep 9, 2019
Page
880
of 928
Rev1.09
IS
D
9
410
0
S
ER
IE
S
T
E
C
HN
ICA
L
RE
F
E
RE
NCE
M
AN
U
AL
1/(1+PCLKDIV)
HIRC
PCLK1
PLLFOUT
HXT
DMICCKEN
(CLK_APBCLK0[15])
11
10
01
00
1/(1+MCLKDIV)
1/4
1
0
CHEN0
(DMIC_CTL[0])
Note:
PCLKDIV = DMIC_DIV[7:0]
MCLKDIV = DMIC_DIV[15:8]
DMIC_MCLK
DMIC Path
(DMIC_CLK)
VAD Path
(VAD_CLK)
DMIC_CLK
D
Q
D
Q
ACTCL (VAD_SINCCTL[30])
ACTIVE
(VAD_STATUS0[31])
ACTCL
(VAD_SINCCTL[30])
VADEN
(VAD_SINCCTL[31])
SW
(VAD_SINCCTL[29])
Figure 6.20-2 VAD Clock Control Diagram
6.20.5.2 VAD Data Control
The VAD data diagram is shown in Figure 6.20-3.
When VAD enabled (VADEN (VAD_SINCCTL[31]) = 1) and voice detected (ACTIVE
(VAD_STATUS0[31]) = 1), the PCM data can be sent to SRAM via PDMA to do key word detection
by software solution. And user can stop sending PCM data to SRAM by setting register DATAOFF
(VAD_SINCCTL[28]).
SINC
Biquad
VAD
[15:0]
SINC
DMIC
[23:0]
1
0
FIFO
0
1
X
DMIC_IN (CH0)
PDMA
VAD Path
DMIC Path
DATAOFF
(VAD_SINCCTL[28])
Note:
X: Data output always be 0
CHEN0
(DMIC_CTL[0])
D
Q
D
Q
ACTCL (VAD_SINCCTL[30])
ACTIVE
(VAD_STATUS0[31])
ACTCL
(VAD_SINCCTL[30])
VADEN
(VAD_SINCCTL[31])
SW
(VAD_SINCCTL[29])