CC2550 Datasheet, PDF (41/50 Pages) Texas Instruments – Single Chip Low Cost Low Power RF-Transmitter

CC2550
0x13: MDMCFG1 – Modulator configuration
Bit Field Name
Reset
R/W Description
7 FEC_EN
0
6:4 NUM_PREAMBLE[2:0] 2 (010)
3:2 Reserved
1:0 CHANSPC_E[1:0]
2 (10)
R/W Enable Forward Error Correction (FEC) with interleaving for
packet payload
0 = Disable
1 = Enable
R/W Sets the minimum number of preamble bytes to be
transmitted
Setting
Number of preamble bytes
0 (000)
2
1 (001)
3
2 (010)
4
3 (011)
6
4 (100)
8
5 (101)
12
6 (110)
16
7 (111)
24
R0
R/W 2 bit exponent of channel spacing
Bit Field Name
7:0 CHANSPC_M[7:0]
0x14: MDMCFG0 – Modulator configuration
Reset
R/W Description
248 (0xF8) R/W 8-bit mantissa of channel spacing (initial 1 assumed). The
channel spacing is multiplied by the channel number CHAN and
added to the base frequency. It is unsigned and has the format:
( ) ∆f_CHANNEL
=
f _{XOSC â‹}
2 ¹⁸
256 + CHANSPC _ M
⋅ 2^{CHANSPC _ E} ⋅ CHAN
The default values give 199.951kHz channel spacing (the
closest setting to 200kHz), assuming 26.0MHz crystal
frequency.
0x15: DEVIATN – Modulator deviation setting
Bit Field Name
Reset
R/W Description
7 Reserved
6:4 DEVIATION_E[2:0]
3 Reserved
4 (100)
R0
R/W Deviation exponent
R0
Preliminary Data Sheet (rev. 1.1) SWRS039
Page 41 of 51