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Ex: RX mode, Input = DEMOD, Output = AUDO(sources = DAC1), Sub-tone = CTCSS,
CTCSS tone=01h
CTCSS Rx mode Setup Flow:
Flow description:
<RSSI OK>: Confirm the RF signal is OK.
<81EC3>: Enable the PGA circuit. PGA on and enable the PGA input source.
<81B30>: Select the PGA audio input source location. Select the PGA input source to be
DEMOD with audio out to be DAC common-mode bias so as to reduce noise.
<81162> Enter the Rx mode. Select the Rx mode and enable the Sub-tone = CTCSS
function.
<Is CTCSS event>：Wait to confirm that this signal has the CTCSS sub-tone of the same
channel.
<81E8B>：Enable the DAC1, Buffer and PGA circuits. DAC1 on and enable the DAC1
output. AUDO output buffer on and enable the audio output circuit. PGA on and enable
the PGA input source.
<81B25>：Select the PGA and Audio input source paths. Select the PGA input source to
be DEMOD, audio out sources to be DAC1 and switch the DAC1 pin source paths to the
internal common-mode bias so as to prevent audio leakage from MOD.
HT98R068 Two-way Radio MCU
17
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