9 configurable start-of-frame delimiter, 1 overview, 2 register description – Rainbow Electronics AT86RF231 User Manual
Page 155: Section 11.9 “configurable start-of
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8111A–AVR–05/08
AT86RF231
• Bit [1:0] - OQPSK_DATA_RATE
Section 11.3 “High Data Rate Modes” on page 137
.
11.9
Configurable Start-Of-Frame Delimiter
11.9.1
Overview
The SFD is a field indicating the end of the SHR and the start of the packet data. The length of
the SFD is 1 octet (2 symbols). This octet is used for byte synchronization only and is not
included in the Frame Buffer.
The value of the SFD could be changed if it is needed to operate non IEEE 802.15.4 compliant
networks. An IEEE 802.15.4 compliant network node does not synchronize to frames with a dif-
ferent SFD value.
Due to the way the SHR is formed, it is not recommended to set the low-order 4 bits to 0.
11.9.2
Register Description
Register 0x0B (SFD_VALUE):
This register contains the one octet start-of-frame delimiter (SFD) to synchronize to a received
frame.
• Bit [7:0] - SFD_VALUE
For compliant IEEE 802.15.4 networks set SFD_VALUE = 0xA7, as specified by
and
. This
is the default value of the register.
To establish non IEEE 802.15.4 compliant networks the SFD value can be changed to any other
value. If enabled an IRQ_2 (RX_START) is issued only if the received SFD matches the register
content of register SFD_VALUE and a valid PHR is received.
Bit
7
6
5
4
3
2
1
0
+0x0B
SFD_VALUE[7:0]
SFD_VALUE
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset Value
1
0
1
0
0
1
1
1