AN2492 Freescale Semiconductor / Motorola, AN2492 Datasheet - Page 10

• Manufacturer Part Number: AN2492
• Description: MPC184 Descriptor Programmers Guide--PCI View
• Manufacturer: Freescale Semiconductor / Motorola

Execution Unit Mode Data
Execution Unit Mode Data
Figure 8 shows the MDEU mode register.
Table 6 describes the MDEU mode register signals.
10
31:11
10:8
Bits
6:5
Reset
Reset
7
4
3
Field
Field
Addr
Addr
R/W
R/W
31
31
Burst size
Signal
HMAC
Cont
INT
—
—
Reserved
MPC184 Descriptor Programmer’s Guide— PCI View
Reserved
processed with a single key/context. The MDEU signals to the crypto-channel that a ‘burst
size’ amount of data is available to be pushed to the FIFO.
Note: The inclusion of this field in the MDEU mode register is to avoid confusing a user
who may read this register in debug mode. Burst size should not be written directly to the
MDEU.
Continue (Cont)—Used during HMAC/HASH processing when the data to be hashed is
spread across multiple descriptors.
0 Don’t Continue—operate the MDEU in auto completion mode
1 Preserve context to operate the MDEU in continuation mode
Reserved
Initialization Bit (INT)—Cause an algorithm-specific initialization of the digest registers.
Most operations will require this bit to be set. Only static operations that are continuing from
a known intermediate hash value would not initialize the registers.
0 Do not initialize
1 Initialize the selected algorithm’s starting registers
Identifies the hash operation to execute:
0 Perform standard hash
1 Perform HMAC operation. This requires a key and key length information.
The MPC184 implements flow control to allow larger than FIFO sized blocks of data to be
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 8. MDEU Mode Register
Table 6. MDEU Mode Register
Go to: www.freescale.com
11
Burst Size
10
MDEU 0x0C000
MDEU 0x0C004
8
Reserved
R/W
R/W
Cont
0
0
7
Description
6
--
5
INT
4
HMAC PD
3
MOTOROLA
2
1
ALG
0
0