Silicon Laboratories Si47 Series Programming Manual page 91

Property 0x1107. FM_ANTENNA_INPUT
Selects what type of antenna and what pin it is connected to. Default is 0 which means the antenna used is a
headphone (long) antenna and it is connected to the FMI pin. Setting the FMTXO bit to 1 means that the antenna
used is an embedded (short) antenna and it is connected to the TXO/LPI pin.
Note: To assure proper tuning, the FM_TUNE_FREQ command should be issued immediately after this property is changed.
Available in: Si4704/05/06/20/21
Default: 0x0000
Bit D15 D14 D13 D12 D11 D10
0 0 0
Name
Bit Name
15:1 Reserved
0 FMTXO
Property 0x1108. FM_MAX_TUNE_ERROR
Sets the maximum freq error allowed before setting the AFC rail indicator (AFCRL). The CTS bit (and optional
interrupt) is set when it is safe to send the next command. This property may only be set or read when in powerup
mode. The default is 20 kHz.
Note: For FMRX components 2.0 or earlier, the default is set to 30 kHz. For best seek performance, set
FM_MAX_TUNE_ERROR to 20 kHz.
Available in: All
Default: 0x001E (Si473x-B20 and earlier)
0x0014 (all others)
Units: kHz
Step: 1
Range: 0–255
Bit D15 D14 D13
0 0 0
Name
Bit Name
15:8 Reserved
7:0 FMMAXTUNEERR
D9
0 0 0 0
Always write to 0
Selects what type of antenna and which pin it is connected to:
0 = Use FMI pin for headphone (long) antenna
1 = Use TXO/LPI pin for embedded (short) antenna
D12 D11 D10 D9
0 0 0 0
Always write to 0.
FM Maximum Tuning Frequency Error.
Maximum tuning error allowed before setting the AFC Rail Indicator ON. Specified in
units of kHz. Default is 20 kHz.
Rev. 0.8
D8 D7 D6 D5 D4
0 0 0 0
Function
D8 D7 D6 D5
0 FMMAXTUNEERR[7:0]
Function
AN332
D3 D2 D1
0 0 0 0 FMTXO
D4 D3 D2 D1
D0
D0
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