MRF24XA_15 Datasheet, PDF (186/258 Pages) Microchip Technology – Low-Power, 2.4 GHz ISM-Band IEEE 802.15.4™ RF

MRF24XA
6.8.7
MAC AND NWK LAYER SECURITY
EXAMPLE 1
• Network Configuration: Address size is 8 bytes
• Source address: 0x0807060504030201, where
LSB (0x01) is at address 0x1F
• Destination address: 0x9897969594939291
• Payload: BA BA
• Network header: AB
• Network payload: AB
• Network security level: 0x07
• MAC security level: 0x03
• MAC security indices: Only encode from the sec-
ond payload
• Packet: Data packet
6.8.7.1 Transmission
1. Host MCU constructs the frame and loads the
buffer:
19 || C9 55 91 92 93 94 95 96 97 98 01 02 03 04
05 06 07 08 || 5E 18 19 || BA BA AB AB
2. Host MCU configures:
- SECSUITE to 0x07
- SECKEY to
0x0F0E0D0C0B0A09080706050403020100,
where LSB (0x00) is at address 0x40
- SECNONCE
0x08070605040302015555555506, where
MSB (0x08) is at address 0x5c.
3. Host MCU issues TXENC.
4. MRF24XA configures:
- SECHDRINDX to 0x18
- SECPAYINDX to 0x19
- SECENDINDX to 0x19.
5. MRF24XA performs CCM* authentication with
encryption, where AB AB is encrypted to AB E6,
and the following MIC tag is attached:
AB 4B 03 7B B7 30 98 B1 E5 93 CA D7 86 81
8A 2D
6. MRF24XA asserts TXENCIF (and IDLEIF).
7. Host MCU configures:
- SECSUITE to 0x03
- SECKEY to 0xFFFEFDFCFB-
FAF9F8F7F6F5F4F3F2F1F0, where LSB
(0xF0) is at address 0x40
- SECNONCE
0xF8F7F6F5F4F3F2F15555555506,
where (0xF8) is at address 0x5c.
8. Host MCU issues TXST.
9. MRF24XA configures:
- SECHDRINDX to 0x01
- SECPAYINDX to 0x17
- SECENDINDX to 0x29.
10. MRF24XA performs CCM* authentication,
where the following MIC tag is attached:
05 15 AB 5F 6C 7D 5C 70 6C 96 91 C0 34 E5
18 0D
11. MRF24XA appends CRC: 0x717B.
12. MRF24XA transmits the packet to the medium.
Different IF is received based on the register
settings (for example, TX with CSMA).
TX Buffer (0x200) content:
3B || C9 55 91 92 93 94 95 96 97 98 01 02 03 04
05 06 07 08 || 5E 18 19 || BA BA AB E6 AB 4B
03 7B B7 30 98 B1 E5 93 CA D7 86 81 8A 2D
05 15 AB 5F 6C 7D 5C 70 6C 96 91 C0 34 E5
18 0D || 7B 71
6.8.7.2 Reception
1. MRF24XA receives the following packet through
the antenna:
3B || C9 55 91 92 93 94 95 96 97 98 01 02 03 04
05 06 07 08 || 5E 18 19 || BA BA AB E6 AB 4B
03 7B B7 30 98 B1 E5 93 CA D7 86 81 8A 2D
05 15 AB 5F 6C 7D 5C 70 6C 96 91 C0 34 E5
18 0D || 7B 71
2. MRF24XA configures:
- SECHDRINDX to 0x01
- SECPAYINDX to 0x17
- SECENDINDX to 0x39.
3. MRF24XA asserts RXIF (RXSFDIF): Packet
accepted by RX filter.
4. —
5. Host MCU configures:
- SECSUITE to 0x03
- SECKEY to 0xFFFEFDFCFB-
FAF9F8F7F6F5F4F3F2F1F0, where LSB
(0xF0) is at address 0x40
- SECNONCE
0xF8F7F6F5F4F3F2F15555555506,
where MSB (0xF8) is at address 0x5c.
6. Host MCU issues RXDEC.
7. MRF24XA performs CCM* de-authentication,
where the MIC tag is compared against the
received one.
8. MRF24XA configures:
- SECHDRINDX to 0x18
- SECPAYINDX to 0x19
- SECENDINDX to 0x29.
9. MRF24XA asserts RXDECIF (and IDLEIF).
10. —
DS70005023B-page 186
Preliminary
 2015 Microchip Technology Inc.