
HT98R068-1 Two-way Radio OTP MCU
Audio Advanced Function
The device provides multiple audio processors, including scrambler, compandor,
emphasis, HPF, LPF…etc. for a wide range of applications. The function switches are
located in I/O CMD-2Ch [7-2]. As the audio processor operating frequencies are different,
there are some restrictions in enabling the function groups and for using the TX/RX. See
the appendix for reference:
Audio Control - 2Ch Address
Bit
7
6
5
4
3
2
1
0
Name
EN_Scram EN_Comp
EN_Emp
EN_NBW
EN_WBW
EN_HPF300 EN_VOX EN_AGC
Advanced Audio Process Control Register
Audio – Low Pass Filter/High Pass Filter Function Set
In a communication system, signal interference and noise from adjacent channels will
destroy the data to be transmitted or received. Suitable filtering can improve this problem.
The device provides a 3.0kHz broad band and a 2.55kHz narrow band for a low pass filter
as well as a 300Hz high pass filter to filte the sub-tones and signals outside the channel.
The control bit I/O CMD-2Ch [4-2] is setup as follows.
12.5k LPF & 300 HPF Enable Flow
Flow description:
<82C14>: Setup data: 14h. 2Ch [4] = 1 enables 12.5k LPF. 2Ch [2] = 1 enables 300Hz
HPF.
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