MRF24XA_15 Datasheet, PDF (138/258 Pages) Microchip Technology – Low-Power, 2.4 GHz ISM-Band IEEE 802.15.4™ RF

MRF24XA
Receiver Side:
1 Description RX Configuration: Security Suite
Example Security Suite = MIC-32
2 Description If RXBUFFUL is 0 then RXSFDIF = 1
If RXBUFFUL is 1 then RXSFDIF = 1 RXOVFIF = 1 (no writing to buffer)
3 Description RX Parsing and Filtering when frame reception is complete.
If packet filtered then RXFLTIF,
Otherwise = 1 (Network secured frame received since SECEN = 0)
Example RXFILTER(@0x18) = 0x45
4 Description Read RX buffer containing PRFR + CRC. CRC is valid for the encrypted frame and, LQI, RSSI
(RSVs) appended to the frame.
Example
18 | 01 98 | A8 | 2C 2D | FF FF | 2C 2D | 1A 1B | 01 02 03 04 05 06 | 46 | 78 C3 22 32 | A7 8E ||
RSVs
CRC: 0xA7 0x8E
5 Description RXDEC = 1 launches decryption and authenticity checking.
6 Description If authenticity is approved (success): RXDECIF = 1. CRC is not valid for the decrypted frame.
Otherwise RXTAGIF = 1.
Example 1A | 01 98 | A8 | 2C 2D | FF FF | 2C 2D | 1A 1B | 01 02 03 04 05 06 | FF | 78 C3 22 32 | A7 8E |6C
42
RSSI: 0x6C
LQI: 0x42
5.1 Frame Types in IEEE
802.15.4-Compliant Framing Mode
The Type<2:0> bit field in FrameCtrl uses the encoding
in Table 5-1.
TABLE 5-1: IEEE 802.15.4™ FRAME TYPES
TYPE Field
b2,b1,b0
Frame Type
Related Hardware Features
000
Beacon
Beacons are a specific type of broadcast frames.
This device does not provide support for MHR-parsing on Beacon frames.
Beacon frames are always accepted as valid frames.
001
Data
This is filtered by setting DATAREJ.
010
Acknowledge Must be generated by the receiver (from SW or HW), if AckReq = 1 in the last
received frame, and must contain the same Sequence value.
This is generated by hardware (AUTOACKEN = 1). In this case it is not loaded
to the TX frame buffer. AUTOACKEN = 1 requires CRCSZ = 1 on both the
transmitter and the receiver side.
011
Command
This is filtered by CMDREJ.
First byte of payload (Command) is never encrypted.
See command encoding in Table 82 in Section 7.3 of IEEE 802.15.4™-2006.
1xx
Reserved
—
If SecEn bit in FrameCtrl is set, the hardware parses
the frame to construct the security material (both at
sending and after reception). In the case of Beacon
frames, it is the responsibility of the host MCU to set the
security materials before transmission (TXST) and
after reception (RXIF).
For Beacon frames, the Frame Version subfield must
be set to ‘1’ if the Security Enabled subfield is set to ‘1’.
DS70005023C-page 138
Preliminary
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