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Displayed in, Figure 22-26 – Freescale Semiconductor MCF5480 User Manual

Page 638

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MCF548x Reference Manual, Rev. 3

22-36

Freescale Semiconductor

Figure 22-26. DEU Status Register (DSR)

Table 22-23

describes the DEU status register’s bit settings.

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

R

0

0

HALT IFW

OFR

IE

ID

RD

0

0

0

0

0

0

0

W

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

R

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

W

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Reg

Addr

MBAR + 0x2A028

Table 22-23. DSR Field Descriptions

Bits

Name

Description

31–30

Reserved

29

HALT

Halt. Indicates that the DEU has halted due to an error.
0 DEU not halted
1 DEU halted
Note: Because the error causing the DEU to stop operating may be masked to the interrupt status
register, the status register is used to provide a second source of information regarding errors
preventing normal operation.

28

IFW

Input FIFO Writable. The controller uses this signal to determine if the DEU can accept the next
burst size block of data.
0 DEU Input FIFO not ready
1 DEU Input FIFO ready
Note: The SEC implements flow control to allow larger than FIFO sized blocks of data to be
processed with a single key/IV. The DEU signals to the crypto-channel that a “burst size” amount of
space is available in the FIFO.

27

OFR

Output FIFO Readable. The controller uses this signal to determine if the DEU can source the next
burst size block of data.
0 DEU Output FIFO not ready
1 DEU Output FIFO ready
Note: The SEC implements flow control to allow larger than FIFO sized blocks of data to be
processed with a single key/IV. The DEU signals to the crypto-channel that a “burst size” amount of
data is available in the FIFO.

26

IE

Interrupt error. This status bit reflects the state of the ERROR interrupt signal, as sampled by the
controller interrupt status register (

Section 22.6.4.4, “SEC Interrupt Status Registers (SISRH and

SISRL)

”).

0 DEU is not signaling error
1 DEU is signaling error

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