HT98R068 Two-way Radio MCU
(2) VOX Signal Status Detect:
Flow description (1):
<81EC7>
：
Enable the MIC and PGA circuits. MIC on–enable the microphone circuit. PGA
on–enable the PGA input source.
<81B10>
：
Select the PGA and Audio input source paths. Select the PGA input source to
be MIC and the audio out to be DAC common-mode bias to reduce the noise.
<81120>
：
Setup to slow mode.
<CTRL2[7-6]=b’00> & <CTRL2[5]=b’1>
：
Set the audio processor to the lowest frequency
-4MHz.
<82C02>
：
Setup data: 02h. 2Ch[1] = 1 enables the VOX function.
Flow description (2):
<Is VOX event>
：
Confirm if it is a VOX event.
<92900>
：
The VOX high/low threshold status. Read the VOX threshold status.
29h[1-0]=b’10, above the high threshold = a VOX event. 29h[1-0]=b’01, below the low
threshold = end a VOX event.
<81120>
：
Go back to the slow mode and wait.
<CTRL2[7-6]=b’11> & <CTRL2[5]=b’0>
：
Set the Audio processor to the maximum
frequency -16MHz (assumed to be the original setup value.)
<Contiune Tx…>
：
Enter the Tx control flow.
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