Specifications

CC1101
SWRS061I Page 75 of 98
0x0B: FSCTRL1 – Frequency Synthesizer Control
Bit
Field Name
Reset
R/W
Description
7:6
R0
Not used
5
0
R/W
Reserved
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[23:0] 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