ISD94100 Series Technical Reference Manual
Sep 9, 2019
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Rev1.09
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VAD Control Register 3 (VAD_CTL3)
Register
Offset
R/W Description
Reset Value
VAD_CTL3
0x1C
R/W VAD Control Register 3
0x0000_7FFF
31
30
29
28
27
26
25
24
HOT
23
22
21
20
19
18
17
16
HOT
15
14
13
12
11
10
9
8
DEVTHRE
7
6
5
4
3
2
1
0
DEVTHRE
Bits
Description
[31:16]
HOT
Hang Over time
Hang Over time setting, means how many clocks (CLKSD) of the ACTIVE
(VAD_STATUS0[31]) staying high when the calculation is no longer bigger than the
threshold
[15:0]
DEVTHRE
Deviation Threshold
To check if the incoming signal is substantially bigger than its background. This may
work to exclude breath sound as it is slowly varying, but not other sounds (e.g.,
footsteps, hand claps) with sudden amplitude increase.
Small: easy to trigger, good for far-field pick-up, but requiring quiet environment.
Large: good for handheld applications, but requiring louder voice to trigger.