Data Sheet
CC1101
SWRS061B Page 68 of 93
0x10: MDMCFG4 – Modem Configuration
Bit Field Name Reset R/W Description
7:6 CHANBW_E[1:0] 2 (0x02) R/W
5:4 CHANBW_M[1:0] 0 (0x00) R/W Sets the decimation ratio for the delta-sigma ADC input stream and thus
the channel bandwidth.
ECHANBW
XOSC
channel
MCHANBW
f
BW
_
2)·_4(8 +⋅
=
The default values give 203 kHz channel filter bandwidth, assuming a 26.0
MHz crystal.
3:0 DRATE_E[3:0] 12 (0x0C) R/W The exponent of the user specified symbol rate
0x11: MDMCFG3 – Modem Configuration
Bit Field Name Reset R/W Description
7:0 DRATE_M[7:0] 34 (0x22) R/W The mantissa of the user specified symbol rate. The symbol rate is
configured using an unsigned, floating-point number with 9-bit mantissa
and 4-bit exponent. The 9
th
bit is a hidden ‘1’. The resulting data rate is:
(
)
XOSC
EDRATE
DATA
f
MDRATE
R ⋅
⋅+
=
28
_
2
2_256
The default values give a data rate of 115.051 kBaud (closest setting to
115.2 kBaud), assuming a 26.0 MHz crystal.