CC2510FX Datasheet, PDF (203/253 Pages) List of Unclassifed Manufacturers – True System-on-Chip with Low Power RF Transceiver and 8051 MCU

CC2510Fx / CC2511Fx
encoding is not supported at the same time as
using the FEC/Interleaver option.
15.9.1 Frequency Shift Keying
2-FSK can optionally be shaped by a
Gaussian filter with BT=1, producing a GFSK
modulated signal.
The frequency deviation is programmed with
the DEVIATION_M and DEVIATION_E values
in the DEVIATN register. The value has an
exponent/mantissa form, and the resultant
deviation is given by:
f_dev =
f _xosc
2¹⁷
⋅ (8 +
DEVIATION
_
M ) ⋅ 2^{DEVIATION _ E}
The symbol encoding is shown in Table 61.
Format
2FSK/GFSK
Symbol
‘0’
‘1’
Coding
– Deviation
+ Deviation
Table 61: Symbol encoding for FSK
modulation
15.9.2 Minimum Shift Keying
When using MSK⁶, the complete transmission
(preamble, sync word and payload) will be
MSK modulated.
Phase shifts are performed with a constant
transition time.
The fraction of a symbol period used to
change the phase can be modified with the
DEVIATN.DEVIATION_M setting. This is
equivalent to changing the shaping of the
symbol.
The MSK modulation format implemented in
CC2510Fx/CC2511Fx inverts the sync word and
data compared to e.g. signal generators.
6 _{Identical to offset QPSK with half-sine}
shaping (data coding may differ)
Another use of the preamble quality threshold
is as a qualifier for the optional RX termination
timer. See section 15.12.3 on page 210 for
details.
The preamble quality estimator increases an
internal counter by one each time a bit is
received that is different from the previous bit,
15.9.3 Amplitude Modulation
The supported amplitude modulation On-Off
Keying (OOK) simply turns on or off the PA to
modulate 1 and 0 respectively.
15.10 Received Signal Qualifiers and Link
Quality Information
CC2510Fx/CC2511Fx has several qualifiers that
can be used to increase the likelihood that a
valid sync word is detected.
15.10.1 Sync Word Qualifier
If sync word detection in RX is enabled in
register MDMCFG2 the CC2510Fx/CC2511Fx will
not start writing received data to the RFD
register and perform the packet filtering
described in section 15.8.3 before a valid sync
word has been detected. The sync word
qualifier mode is set by MDMCFG2.SYNC_MODE
and is summarized in Table 62. Carrier sense
in Table 62 is described in section 15.10.4
MDMCFG2.
SYNC_MODE
000
001
010
011
100
101
110
111
Sync word qualifier mode
No preamble/sync
15/16 sync word bits detected
16/16 sync word bits detected
30/32 sync word bits detected
No preamble/sync, carrier sense
above threshold
15/16 + carrier sense above threshold
16/16 + carrier sense above threshold
30/32 + carrier sense above threshold
Table 62: Sync word qualifier mode
15.10.2 Preamble Quality Threshold (PQT)
The Preamble Quality Threshold (PQT) sync-
word qualifier adds the requirement that the
received sync word must be preceded with a
preamble with a quality above the
programmed threshold.
and decreases the counter by 4 each time a
bit is received that is the same as the last bit.
The counter saturates at 0 and 31. The
threshold is configured with the register field
PKTCTRL1.PQT. A threshold of 4·PQT for this
counter is used to gate sync word detection.
CC2510Fx/CC2511Fx PRELIMINARY Data Sheet (Rev. 1.2) SWRS055A Page 203 of 252