SEC Lite Execution Units
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
48-27
Figure 48-19. AESU Key Size Register
48.3.4
AESU Data Size Register
This AESU Data Size Register is used to verify that the data to be processed by the AESU is divisible by
the AES algorithm block size of 128-bits. The AESU does not automatically pad messages out to 128-bit
blocks, therefore any message processed by the AESU must be divisible by 128-bits or a data size error
will occur.
In normal operation, the full message length to be encrypted or decrypted with the AESU is copied from
the descriptor to the AESU data size register, however only bits 1:7 are checked to determine if there is a
data size error. If 1:7 are all zeroes, the message is evenly divisible into 128-bit blocks.
This register is cleared when the AESU is reset or re-initialized. If a data size other than 128-bits is
specified, an illegal data size error will be generated. Writing to this register signals the AESU to start
processing data from the input FIFO as soon as it is available. If the value of data size is modified during
processing, a context error will be generated.
0
1
2
7
8
31
Field
—
Key Size
—
msb<—lsb
Reset
0x0000_0000
R/W
R/W
Addr
AESU 0x04008
0
31
Field
Reserved
Reset
0x0000_0000
R/W
R/W
Addr
AESU 0x0400C
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...