CC2510FX Datasheet, PDF (202/253 Pages) List of Unclassifed Manufacturers – True System-on-Chip with Low Power RF Transceiver and 8051 MCU

CC2510Fx / CC2511Fx
15.8.3 Packet filtering in Receive Mode
CC2510Fx/CC2511Fx supports two different
packet-filtering criteria: address filtering and
maximum length filtering.
15.8.3.1 Address Filtering
Setting PKTCTRL1.ADR_CHK to any other
value than zero enables the packet address
filter. The packet handler engine will compare
the destination address byte in the packet with
the programmed node address in the ADDR
register and the 0x00 broadcast address when
PKTCTRL1.ADR_CHK=10 or both 0x00 and
0xFF broadcast addresses when
PKTCTRL1.ADR_CHK=11. If the received
address matches a valid address, the packet
is accepted and a RFTXRX interrupt and a
DMA trigger is generated. If the address match
fails, the packet is discarded and receive
mode restarted (regardless of the
MCSM1.RXOFF_MODE setting).
If the received address matches a valid
address when the packet length is set to
infinite and address filtering is enabled, the
first byte read from the radio will be 0xFF,
followed by the address byte and then the
payload data.
15.8.3.2 Maximum Length Filtering
In the variable packet length mode the
PKTLEN.PACKET_LENGTH register value is
used to set the maximum allowed packet
length. If the received length byte has a larger
value than this, the packet is discarded and
receive mode restarted (regardless of the
MCSM1.RXOFF_MODE setting).
15.8.4 Packet Handling in Transmit Mode
The payload that is to be transmitted must be
written into RFD. The first byte written must be
the length byte when variable packet length is
enabled. The length byte has a value equal to
the payload of the packet (including the
optional address byte). If fixed packet length is
enabled, then the first byte written to RFD is
interpreted as the destination address, if this
feature is enabled in the device that receives
the packet.
The modulator will first send the programmed
number of preamble bytes. If data is written to
RFD, the modulator will send the two-byte
(optionally 4-byte) sync word and then the
payload written to RFD. If CRC is enabled, the
checksum is calculated over all the data pulled
from RFD and the result is sent as two extra
bytes at the end of the payload data.
If whitening is enabled, the length byte,
payload data and the two CRC bytes will be
whitened. This is done before the optional
FEC/Interleaver stage. Whitening is enabled
by setting PKTCTRL0.WHITE_DATA=1.
If FEC/Interleaving is enabled, the length byte,
payload data and the two CRC bytes will be
scrambled by the interleaver, and FEC
encoded before being modulated.
15.8.5 Packet Handling in Receive Mode
In receive mode, the demodulator and packet
handler will search for a valid preamble and
the sync word. When found, the demodulator
has obtained both bit and byte synchronism
and will receive the first payload byte.
If FEC/Interleaving is enabled, the FEC
decoder will start to decode the first payload
byte. The interleaver will de-scramble the bits
before any other processing is done to the
data.
If whitening is enabled, the data will be de-
whitened at this stage.
When variable packet length is enabled, the
first byte is the length byte. The packet handler
stores this value as the packet length and
receives the number of bytes indicated by the
length byte. If fixed packet length is used, the
packet handler will accept the programmed
number of bytes.
Next, the packet handler optionally checks the
address and only continues the reception if the
address matches. If automatic CRC check is
enabled, the packet handler computes CRC
and matches it with the appended CRC
checksum.
At the end of the payload, the packet handler
will optionally write two extra packet status
bytes that contain CRC status, link quality
indication and RSSI value.
15.9 Modulation Formats
CC2510Fx/CC2511Fx supports amplitude,
frequency and phase shift modulation formats.
The desired modulation format is set in the
MDMCFG2.MOD_FORMAT register.
Optionally, the data stream can be Manchester
coded by the modulator and decoded by the
demodulator. This option is enabled by setting
MDMCFG2.MANCHESTER_EN=1. Manchester
CC2510Fx/CC2511Fx PRELIMINARY Data Sheet (Rev. 1.2) SWRS055A Page 202 of 252