LMX5001VBC NSC [National Semiconductor], LMX5001VBC Datasheet - Page 10

• Manufacturer Part Number: LMX5001VBC
• Description: Dedicated Bluetooth Link Controller
• Manufacturer: NSC [National Semiconductor]

www.national.com
Functional Description
ENCRYPTION ENGINE
A Bluetooth encryption engine is implemented in the
LMX5001. The algorithm of the engine follows figure 14.6
and Steps 2, 3 and 4 in section 14.3.5 of the Bluetooth
Specification 1.0A. The encryption engine initialization is car-
ried out over the LCI. It occurs after system load and before
the actual data transmission/receiving. 208 initialization bits
are loaded to LMX5001 after the system load. The LMX5001
The 28 Encryption Initialization bytes are detailed in Table 6 below:
Byte No.
Byte 10
Byte 11
Byte 12
Byte 13
Byte 14
Byte 15
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Byte 9
Kc’[11]
Kc’[13]
Kc’[15]
Kc’[1]
Kc’[3]
Kc’[5]
Kc’[7]
Kc’[9]
Bit 7
FIGURE 5. Transmit with encryption enabled (command code 0x13 or 0x16)
FIGURE 4. Receive with encryption enabled (command code 0x12 or 0x15)
0
0
0
0
0
0
0
0
Bit 6
(Continued)
TABLE 6. Encryption Initialization Bytes
Bit 5
Kc’[10]
Kc’[12]
Kc’[14]
CL[0]
CL[0]
Kc’[0]
Kc’[2]
Kc’[4]
Kc’[6]
Kc’[8]
U
L
6
6
6
6
6
6
6
6
10
Bit 4
…Kc’[0]
…Kc’[2]
…Kc’[4]
…Kc’[6]
…Kc’[8]
…Kc’[10]
…Kc’[12]
…Kc’[14]
then runs the encryption initialization for 26 µs. After encryp-
tion initialization the first 60 bytes of the “encryption stream
Z
get the encrypted transmit data ready. The 60 byte lead time
is needed only for transmit, but it is sent regardless the type
of transaction to reduce the firmware complexity. The conse-
quent bytes in the encryption stream are piggy-backed with
the packet data once the transition starts. The encryption en-
abled data transfer activity on LCI is illustrated in the figures
below:
t
” is sent back to the LMC to allow firmware enough time to
0
0
0
0
0
Kc’[11]
0
0
0
Kc’[1]
Kc’[3]
Kc’[5]
Kc’[7]
Kc’[9]
Bit 3
7
7
7
7
7
7
…Kc’[1]
…Kc’[3]
…Kc’[5]
…Kc’[7]
…Kc’[9]
…Kc’[11]
1
1
1
1
1
1
Bit 2
0
1
Bit 1
0
1
DS101340-5
DS101340-6
Kc’[10]
Kc’[0]
Kc’[2]
Kc’[4]
Kc’[6]
Kc’[8]
Bit 0
CL
CL
1
1
24
25
7
7
7
7
7
7