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8168C-MCU Wireless-02/10
AT86RF212
Note that in addition to these general rules, IEEE 802.15.4 further restricts the valid
address combinations for the different MAC frame types. For example, the situation
where both addresses are omitted (source addressing mode = 0 and destination
addressing mode = 0) is only allowed for acknowledgment frames. The Frame Filter in
the AT86RF212 has been designed to apply to IEEE 802.15.4 compliant frames. It can
be configured to handle other frame formats and exceptions.
6.1.2.6 Auxiliary Security Header
The Auxiliary Security Header terminates the MHR. This field has a variable length and
specifies information required for security processing, including how the frame is
actually protected (security level) and which keying material from the MAC security PIB
is used (see [2], section 7.6.1). This field shall be present only if the Security Enabled
subfield b3 (see section
6.1.2.3) is set to one. For details on formatting, see section
7.6.2 of [2].
6.1.2.7 MAC Service Data Unit (MSDU)
This is the actual MAC payload. It is usually structured according to the individual frame
type descriptions in IEEE 802.15.4 standard.
6.1.2.8 MAC Footer (MFR)
The MAC footer consists of a two-octet Frame Checksum (FCS). For details, refer to
6.2 Frame Filter
Frame Filtering is a procedure that evaluates whether or not a received frame matches
predefined criteria, like source or destination address or frame types. A filtering
procedure as described in IEEE 802.15.4-2006 (section 7.5.6.2, third level of filtering) is
applied to the frame to accept a received frame and to generate the address match
interrupt IRQ_5 (AMI).
The AT86RF212 Frame Filter passes only frames that satisfy all of the following
requirements/rules (quote from IEEE 802.15.4-2006, section 7.5.6.2):
1. The Frame Type subfield shall not contain a reserved frame type.
2. The Frame Version subfield shall not contain a reserved value.
3. If a destination PAN identifier is included in the frame, it shall match macPANId or
shall be the broadcast PAN identifier (0xFFFF).
4. If a short destination address is included in the frame, it shall match either
macShortAddress or the broadcast address (0xFFFF). Otherwise, if an extended
destination address is included in the frame, it shall match aExtendedAddress.
5. If the frame type indicates that the frame is a beacon frame, the source PAN identifier
shall match macPANId unless macPANId is equal to 0xffff, in which case the beacon
frame shall be accepted regardless of the source PAN identifier.
6. If only source addressing fields are included in a data or MAC command frame, the
frame shall be accepted only if the device is the PAN coordinator and the source
PAN identifier matches macPANId.
Moreover the AT86RF212 has two additional requirements:
7. The frame type shall indicate that the frame is not an acknowledgment (ACK) frame.
8. At least one address field must be configured.