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6-4
MPC180E Security Processor User’s Manual
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Operational Registers
6.1.3 Status Register (MSR)
The status register contains bits that give information about the state of the MDEU. Upon
completion of a hash, DONE is asserted in bit 0 of MSR, followed by an interrupt on IRQ
if interrupts are enabled. In addition, whenever the contents of the message buffer are
copied for internal hash processing, BE is asserted. Assertion of BE will cause an interrupt
only if interrupts are enabled and buffer-empty interrupt is enabled (MCR:BIE is asserted).
Address Error (AE) is asserted by addressing MDEU but not specifying a valid address
within MDEU.
The MSR is effectively a read-only register. Its contents cannot be modified by the host
processor except to be reset, which occurs when the host processor performs a write to the
MSR, regardless of the data value.
Figure 6-2 shows the MDEU status register and Table 6-3 describes this register’s fields.
0
15
Field
—
Reset
0000_0000
R/W
R/W
16
27
28
29
30
31
Field
—
IRQ
AE
BE
DONE
Reset
0000_0000
R/W
R/W
Addr
0x016
Figure 6-2. MDEU Status Register (MSR)
Table 6-3. MSR Field Descriptions
Bits
Name
Description
0–27
–
Reserved, should be cleared.
28
IRQ
0 interrupt not indicated
1 interrupt indicated
29
AE
0 address error not detected
1 address error detected
30
BE
0 message buffer not empty
1 message buffer empty
31
DONE
0 hash not completed
1 hash completed
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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m
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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..