Texas Instruments 3138 155 232931 - Manual (Page 70)

CC2420
SWRS041B Page 70 of 89
SECCTRL0 (0x19) - Security Control Register
Bit Field Name Reset R/W Description
15:10 - 0 W0 Reserved, write as 0
9 RXFIFO_PROTECTION 1 R/W Protection enable of the RXFIFO, see description in the RXFIFO
overflow section on page 33. Should be cleared if MAC level
security is not used or is implemented outside CC2420.
8 SEC_CBC_HEAD 1 R/W Defines what to use for the first byte in CBC-MAC (does not
apply to CBC-MAC part of CCM):
0 : Use the first data byte as the first byte into CBC-MAC
1 : Use the length of the data to be authenticated (calculated as
(the packet length field – SEC_TXL – 2) for TX or using SEC_RXL
for RX) as the first byte into CBC-MAC (before the first data
byte).
This bit should be set high for CBC-MAC 802.15.4 inline security.
7 SEC_SAKEYSEL 1 R/W Stand Alone Key select
0 : Key 0 is used
1 : Key 1 is used
6 SEC_TXKEYSEL 1 R/W TX Key select
0 : Key 0 is used
1 : Key 1 is used
5 SEC_RXKEYSEL 0 R/W RX Key select
0 : Key 0 is used
1 : Key 1 is used
4:2 SEC_M[2:0] 1 R/W Number of bytes in authentication field for CBC-MAC, encoded
as (M-2)/2
0 : Reserved
1 : 4
2 : 6
3 : 8
4 : 10
5 : 12
6 : 14
7 : 16
1:0 SEC_MODE[1:0] 0 R/W Security mode
0 : In-line security is disabled
1 : CBC-MAC
2 : CTR
3 : CCM