CC1101_15 Datasheet, PDF (75/105 Pages) Texas Instruments – Low-Power Sub-1 GHz RF Transceiver

CC1101
Bit Field Name
7:6
5
4:0 FREQ_IF[4:0]
0x0B: FSCTRL1 – Frequency Synthesizer Control
Reset
R/W Description
0
15 (0x0F)
R0 Not used
R/W Reserved
R/W The desired IF frequency to employ in RX. Subtracted from FS base frequency
in RX and controls the digital complex mixer in the demodulator.
f _IF

f _XOSC
2¹⁰
 FREQ _ IF
The default value gives an IF frequency of 381kHz, assuming a 26.0 MHz
crystal.
0x0C: FSCTRL0 – Frequency Synthesizer Control
Bit Field Name
Reset
R/W Description
7:0 FREQOFF[7:0] 0 (0x00)
R/W Frequency offset added to the base frequency before being used by the
frequency synthesizer. (2s-complement).
Resolution is FXTAL/2¹⁴ (1.59kHz-1.65kHz); range is ±202 kHz to ±210 kHz,
dependent of XTAL frequency.
Bit Field Name
7:6 FREQ[23:22]
5:0 FREQ[21:16]
0x0D: FREQ2 – Frequency Control Word, High Byte
Reset
R/W Description
0 (00)
30 (0x1E)
R
FREQ[23:22] is always 0 (the FREQ2 register is less than 36 with 26-27 MHz
crystal)
R/W FREQ[23:0] is the base frequency for the frequency synthesiser in
increments of fXOSC/2¹⁶.
  f_carrier 
f _XOSC
2¹⁶
 FREQ
23: 0
Bit Field Name
7:0 FREQ[15:8]
0x0E: FREQ1 – Frequency Control Word, Middle Byte
Reset
R/W Description
196 (0xC4) R/W Ref. FREQ2 register
Bit Field Name
7:0 FREQ[7:0]
0x0F: FREQ0 – Frequency Control Word, Low Byte
Reset
R/W Description
236 (0xEC) R/W Ref. FREQ2 register
SWRS061I
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