MRF24XA_15 Datasheet, PDF (50/258 Pages) Microchip Technology – Low-Power, 2.4 GHz ISM-Band IEEE 802.15.4™ RF

MRF24XA
REGISTER 2-32:
R-0
r
bit 7
SECHDRINDX (SECURITY HEADER INDEX REGISTER)
R/W/HS-0000000
SECHDRINDX<6:0>
ADDRESS: 0x2B
bit 0
Legend: R = Readable bit W = Writable bit
-n = Value at POR
‘1’ = Bit is set
r = Reserved
HS = Hardware Set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
bit 6-0
Reserved: Maintain as ‘0’
SECHDRINDX<6:0>: Security Header Index Field bits
This field defines the portion of the header which performs the authentication operations.
For MAC layer security, SECHDRINDX<6:0> is defined as the address offset of the MAC header from
the beginning of the frame, as stored in the buffer (0 = Length field, 1 = FrameCtrl field, and so on), and
is automatically loaded for both 802.15.4 and Proprietary frames⁽¹⁾.
For Network layer security, SECHDRINDX<6:0> is defined as the address offset of the Network Header
from the beginning of the frame and the Host Controller loads it only for 802.15.4 frames. Note that for
Proprietary frames, the MAC automatically loads it.
Note 1: Setting the DTSM bit disables the automatic computation of this field in TX mode.
REGISTER 2-33:
R-0
r
bit 7
SECPAYINDX (SECURITY PAYLOAD INDEX REGISTER)
R/W/HS-0000000
SECPAYINDX<6:0>
ADDRESS: 0x2C
bit 0
Legend: R = Readable bit W = Writable bit
-n = Value at POR
‘1’ = Bit is set
r = Reserved
HS = Hardware Set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
bit 6-0
Reserved: Maintain as ‘0’
SECPAYINDX<6:0>: Security Payload Index Field bits
This field defines the portion of the payload, which the encryption/decryption operations are performed.
For MAC layer security, SECPAYINDX<6:0> is defined as the address offset of the MAC payload from
the beginning of the frame, as stored in the buffer (0 = Length field, 1 = FrameCtrl field, and so on), and
is automatically loaded for both 802.15.4 and Proprietary frames⁽¹⁾.
For Network layer security, SECPAYINDX<6:0> is defined as the address offset of the payload from the
beginning of the frame and the Host Controller loads it only for 802.15.4 frames. Note that for Propri-
etary frames, the MAC automatically loads it.
Note 1: Setting the DTSM bit disables the automatic computation of this field in TX mode.
DS70005023C-page 50
Preliminary
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