Freescale Semiconductor MCF5480 - Manual (Page 642)

MCF548x Reference Manual, Rev. 3
22-40 Freescale Semiconductor
22.10 Message Digest Execution Unit (MDEU)
This section contains details about the message digest execution unit (MDEU), including register details.
22.10.1 MDEU Register Map
The registers used in the MDEU are documented primarily for debug and target mode operations. If the
requires the use of the MDEU when acting as an initiator, accessing these registers directly is unnecessary.
The device drivers and the on-chip controller will abstract register level access from the user.
The MDEU contains the following registers:
• Reset control register
• Status register
• Interrupt status register
• Interrupt control register
25 OFU Output FIFO underflow. The DEU output FIFO has been read while empty.
0 Output FIFO underflow error enabled
1 Output FIFO underflow error disabled
24-22 — Reserved
21 KPE Key Parity error. The defined parity bits in the keys written to the key registers did not reflect odd
parity correctly. (Note that key register 2 and key register 3 are only checked for parity if the
appropriate DEU mode register bit indicates triple DES.
0 Key parity enabled
1 Key parity error disabled
20 IE Internal error. An internal processing error was detected while performing encryption.
0 Internal error enabled
1 Internal error disabled
19 ERE Early read error. The DEU IV register was read while the DEU was performing encryption.
0 Early read error enabled
1 Early read error disabled
18 CE Context error. A DEU key register, the key size register, the data size register, the mode register, or
IV register was modified while DEU was performing encryption.
0 Context error enabled
1 Context error disabled
17 KSE Key size error. An inappropriate value (8 being appropriate for single DES, and 16 and 24 being
appropriate for Triple DES) was written to the DEU key size register
0 Key size error enabled
1 Key size error disabled
16 DSE Data size error (DSE): A value was written to the DEU data size register that is not a multiple of 8
bytes.
0 Data size error enabled
1 Data size error disabled
15-0 — Reserved
Table 22-25. DIMR Field Descriptions (Continued)
Bits Name Description