Rainbow Electronics AT86RF231 - Manual (Page 80)

80
8111A–AVR–05/08
AT86RF231
Received frames with a frame length field set to 0x00 (invalid PHR) are not signaled to the
microcontroller.
Table 8-1 on page 80 summarizes the type of payload versus the frame length value.
8.1.2 MAC Protocol Layer Data Unit (MPDU)
Figure 8-2 on page 80 shows the frame structure of the MAC layer.
Figure 8-2. IEEE 802.15.4 Frame Format - MAC-Layer Frame Structure (MPDU)
8.1.2.1 MAC Header (MHR) Fields
The MAC header consists of the Frame Control Field (FCF), a sequence number, and the
addressing fields (which are of variable length, and can even be empty in certain situations).
8.1.2.2 Frame Control Field (FCF)
The FCF consists of 16 bits, and occupies the first two octets of the MPDU or PSDU,
respectively.
Figure 8-3. IEEE 802.15.4-2006 Frame Control Field (FCF)
Table 8-1. Frame Length Field - PHR
Frame Length Value Payload
0 - 4 Reserved
5 MPDU (Acknowledgement)
6 - 8 Reserved
9 - aMaxPHYPacketSize MPDU
Frame Control Field 2 octets
Frame
Pending
Reserved Frame Version
ACK
Request
Intra
PAN Destination
addressing mode
Source
addressing mode
Sec.
Enabled
(MFR) MAC Service Data Unit (MSDU)
MAC Protocol Data Unit (MPDU)
MAC Payload FCS
Frame Type
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
MAC Header (MHR)
FCF Addressing Fields
Sequence
Number
2 octets
CRC-16
0/5/6/10/14 octets
Auxiliary Security Header
0/4/6/8/10/12/14/16/18/20 octets
Destination
PAN ID
Destination
address
Source
PAN ID
Source
address
Frame Control Field 2 octets
Frame
Pending
Reserved Frame Version
ACK
Request
Intra
PAN Destination
addressing mode
Source
addressing mode
Sec.
Enabled
Frame Type
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15