CC2510FX Datasheet, PDF (201/253 Pages) List of Unclassifed Manufacturers – True System-on-Chip with Low Power RF Transceiver and 8051 MCU

CC2510Fx / CC2511Fx
15.8.2.1 Arbitrary length field configuration
The fixed length field can be
reprogrammed during receive and
transmit. This opens the possibility to have
a different length field configuration than
supported for variable length packets. At
the start of reception, the packet length is
set to a large value. The CPU reads out
enough bytes to interpret the length field in
the packet. Then the PKTLEN value is set
according to this value. The end of packet
will occur when the byte counter in the
packet handler is equal to the PKTLEN
register. Thus, the CPU must be able to
program the correct length, before the
internal counter reaches the packet length.
By utilizing the infinite packet length
option, arbitrary packet length is available.
At the start of the packet, the infinite mode
must be active. On the TX side, the
PKTLEN register is set to mod(length,
256). On the RX side the MCU reads out
enough bytes to interpret the length field in
the packet and sets the PKTLEN register
to mod(length, 256). When less than 256
bytes remains of the packet the MCU
disables infinite packet length and
activates fixed length packets. When the
internal byte counter reaches the PKTLEN
value, the transmission or reception ends.
Automatic CRC appending/checking can
be used (by setting PKTCTRL0.CRC_EN
to 1)
When for example a 600-byte packet is to
be transmitted, the MCU should do the
following (see also Figure 47):
• Set PKTCTRL0.LENGTH_CONFIG=2
(10).
• Pre-program the PKTLEN register to
mod(600,256)=88.
• Transmit at least 345 bytes.
• Set PKTCTRL0.LENGTH_CONFIG=0
(00).
• The transmission ends when the
packet counter reaches 88. A total of
600 bytes are transmitted.
Internal byte counter in packet handler counts from 0 to 255 and then starts at 0 again
0,1,.......... ,88,.................... 255,0,........,88,.................. ,255,0,........,88,.................. ,255,0,.......................
Infinite packet length enabled
Fixed packet length
enabled when less than
256 bytes remains of
packet
600 bytes transmitted and
received
Length field transmitted and received. Rx and Tx PKTLEN value set to mod(600,256) = 88
Figure 47: Arbitary length field configuration
CC2510Fx/CC2511Fx PRELIMINARY Data Sheet (Rev. 1.2) SWRS055A Page 201 of
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