Data Sheet

CC1101
SWRS061B Page 67 of 93
0x0B: FSCTRL1 – Frequency Synthesizer Control
Bit Field Name Reset R/W Description
7:5 Reserved R0
4:0 FREQ_IF[4:0] 15 (0x0F) 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.
IFFREQ
f
f
XOSC
IF
_
2
10
⋅=
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 F
XTAL
/2
14
(1.59kHz-1.65kHz); range is ±202 kHz to ±210 kHz,
dependent of XTAL frequency.
0x0D: FREQ2 – Frequency Control Word, High Byte
Bit Field Name Reset R/W Description
7:6 FREQ[23:22] 0 (00) R
FREQ[23:22] is always 0 (the FREQ2 register is less than 36 with 26-27
MHz crystal)
5:0 FREQ[21:16] 30 (0x1E) R/W
FREQ[23:22] is the base frequency for the frequency synthesiser in
increments of F
XOSC
/2
16
.
[] 0:23
2
16
FREQ
f
f
XOSC
carrier
⋅=
0x0E: FREQ1 – Frequency Control Word, Middle Byte
Bit Field Name Reset R/W Description
7:0 FREQ[15:8] 196 (0xC4) R/W
Ref. FREQ2 register
0x0F: FREQ0 – Frequency Control Word, Low Byte
Bit Field Name Reset R/W Description
7:0 FREQ[7:0] 236 (0xEC) R/W
Ref. FREQ2 register