
. . . . .
A E S D A T A E N C R Y P T I O N / D E C R Y P T I O N M O D U L E
CCM mode
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For encryption, software must set up this buffer descriptor sequence: Key,
Nonce, additional data (optional), data (used to compute the authentication
code), data (used to perform the actual encryption).
For decryption, software must set up this buffer descriptor sequence: Key,
Nonce, Data (used to perform the actual decryption), Additional data
(optional), Data (used to compute the authentication code).
Note:
The data must be DMA’ed through the AES module twice in CCM mode for
both encryption and decryption modes.
Nonce buffer
This is the format of the Nonce buffer:
Processing flow
This is the CCM buffer descriptor processing flow:
Bits
127:120
119:8*L-par
8*L-par-1:0
Contents
reserved
Nonce
Message length
Key Buffer
Data Buffer Pass
1
(authentication )
Additional
Authentication
Data
(optional )
Nonce
Data Buffer Pass
2
(encryption )
Authentication
Code
Encrypted Data
Source DMA
Operations
Destination DMA
Operations
CCM Mode Encryption
Key Buffer
Data Buffer Pass
2
(authentication )
Additional
Authentication
Data
(optional )
Nonce
Data Buffer Pass
1
(decryption )
Authentication
Code
Decrypted Data
Source DMA
Operations
Destination DMA
Operations
CCM Mode Decryption
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
Page 4: ......
Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...