CC2520_11 Datasheet, PDF (99/133 Pages) Texas Instruments – 2.4 GHZ IEEE 802.15.4/ZIGBEE RF TRANSCEIVER

CC2520 DATASHEET
2.4 GHZ IEEE 802.15.4/ZIGBEE® RF TRANSCEIVER
SWRS068 – DECEMBER 2007
26.9.1 Authentication Only Using CCM*
This example uses a MAC beacon frame and demonstrates how to apply authentication using the
CCM/UCCM instructions.
//Write frame data to RAM
//Start at address 0x200
MEMWR(A={02 00} D={08 d0 84 21 43 01 00 00 00 00 48 de ac 02 05 00 00 00 55 cf 00 00 51 52 53 54})
//Write key to RAM in reverse byte order
//Start at address 0x230
MEMWR(A={02 30} D={cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0})
//Write concatenation of flags, nonce and counter to RAM in reversed byte order
//Start at address 0x240
MEMWR(A={02 40} D={00 00 02 05 00 00 00 01 00 00 00 00 48 de ac 09})
//Do CCM operation with high priority
//Append the output to the frame data (by setting the output address E to 0x000)
CCM(P={01} K={23} C={00} N={24} A={200} E={000} F={1a} M={02})
The expected output from the CCM instruction is {22 3B C1 EC 84 1A B5 53}.
To verify the authentication code in the receiver, the following steps are required.
It is assumed that frame data is already present in RAM from address 0x200.
//Write key to RAM in reverse byte order
//Start at address 0x230
MEMWR(A={02 30} D={cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0})
//Write concatenation of flags, nonce and counter to RAM in reversed byte order
//Start at address 0x240
MEMWR(a={02 40} D={00 00 02 05 00 00 00 01 00 00 00 00 48 de ac 09})
//Do UCCM operation with low priority
UCCM(P={00} K={23} C={00} N={24} A={200} E={2c0} F={1a} M={02})
//Read DPUSTAT register at address 0x02C to check whether the authentication passed or not
REGRD(A={2c})
26.9.2 Encryption Only Using CCM*
This example uses a MAC data frame and demonstrates how to apply encryption/decryption of the payload
using the CCM/UCCM instructions.
//Write frame data to RAM
//Start at address 0x200
MEMWR(A={02 00} D={69 dc 84 21 43 02 00 00 00 00 48 de ac 01 00 00 00 00 48 de ac 04 05 00 00 00 61
62 63 64})
//Write key to RAM in reverse byte order
//Start at address 0x230
MEMWR(A={02 30} D={cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0})
//Write concatenation of flags, nonce and counter to RAM in reversed byte order
//Starting at address 0x240
MEMWR(A={02 40} D={00 00 04 05 00 00 00 01 00 00 00 00 48 de ac 01})
//Do CCM instruction.
CCM(P={01} K={23} C={04} N={24} A={200} E={2c0} F={1a} M={00})
The expected output from the CCM instruction is {D4 3E 02 2B}.
To decrypt the frame in the receiver, the following steps are required. It is assumed that the packed data is
already present in RAM from address 0x200.
//Write key to RAM in reverse byte order
//Start at address 0x230
MEMWR(A={02 30} D={cf ce cd cc cb ca c9 c8 c7 c6 c5 c4 c3 c2 c1 c0})
//Write concatenation of flags, nonce and counter to RAM in reversed byte order
//Starting at address 0x240
MEMWR(A={02 40} D={00 00 04 05 00 00 00 01 00 00 00 00 48 de ac 01})
//Decrypt the frame data and put the plaintext at address 0x2C0.
UCCM(P={01} K={23} C={04} N={24} A={200} E={2c0} F={1a} M={00})
The expected output from the CCM instruction is {61 62 63 64}.
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