CC2550_06 Datasheet, PDF (41/55 Pages) Texas Instruments – Single Chip Low Cost Low Power RF Transmitter

CC2550
Bit Field Name
7:0 DRATE_M[7:0]
0x11: MDMCFG3 – Modulator configuration
Reset
R/W Description
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:
( ) _{RDATA =}
256 + DRATE _ M
2²⁸
⋅ 2^{DRATE _ E} _{⋅ f XOSC}
The default values give a data rate of 115.051 kbps (closest
setting to 115.2 kbps), assuming a 26.0 MHz crystal.
0x12: MDMCFG2 – Modulator configuration
Bit Field Name
Reset R/W Description
7 Reserved
6:4 MOD_FORMAT[2:0]
3 MANCHESTER_EN
2:0 SYNC_MODE[2:0]
R0
1 (001) R/W
0
R/W
2 (010) R/W
The modulation format of the radio signal
Setting Modulation format
0 (000) FSK
1 (001) GFSK
2 (010) -
3 (011) OOK
4 (100) -
5 (101) -
6 (110) -
7 (111) MSK
Enables Manchester encoding/decoding
0 = Disable
1 = Enable
Combined sync-word qualifier mode.
The values 0 (000) and 4 (100) disables preamble
and sync word transmission. The values 1 (001), 2
(001), 5 (101) and 6 (110) enables 16-bit sync word
transmission. The values 3 (011) and 7 (111)
enables repeated sync word transmission. The table
below lists the meaning of each mode (for
compatibility with the CC2500 transceiver):
Setting Sync-word qualifier mode
0 (000) No preamble/sync word
1 (001) 15/16 sync word bits detected
2 (010) 16/16 sync word bits detected
3 (011) 30/32 sync word bits detected
4 (100) No preamble/sync, carrier-sense
above threshold
5 (101) 15/16 + carrier-sense above threshold
6 (110) 16/16 + carrier-sense above threshold
7 (111) 30/32 + carrier-sense above threshold
PRELIMINARY Data Sheet (Rev.1.2) SWRS039A
Page 41 of 54