SAM3S8B Atmel Corporation, SAM3S8B Datasheet - Page 199

• Manufacturer Part Number: SAM3S8B
• Manufacturer: Atmel Corporation

10.22.2
• PRIVDEFENA
Enables privileged software access to the default memory map:
0 = If the MPU is enabled, disables use of the default memory map. Any memory access to a location not covered by any
enabled region causes a fault.
1 = If the MPU is enabled, enables use of the default memory map as a background region for privileged software
accesses.
When enabled, the background region acts as if it is region number -1. Any region that is defined and enabled has priority
over this default map.
If the MPU is disabled, the processor ignores this bit.
• HFNMIENA
Enables the operation of MPU during hard fault, NMI, and FAULTMASK handlers.
When the MPU is enabled:
0 = MPU is disabled during hard fault, NMI, and FAULTMASK handlers, regardless of the value of the ENABLE bit
1 = the MPU is enabled during hard fault, NMI, and FAULTMASK handlers.
When the MPU is disabled, if this bit is set to 1 the behavior is Unpredictable.
• ENABLE
Enables the MPU:
0 = MPU disabled
1 = MPU enabled.
When ENABLE and PRIVDEFENA are both set to 1:
For privileged accesses, the default memory map is as described in
software that does not address an enabled memory region behaves as defined by the default memory map.
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
31
23
15
7
MPU Control Register
30
22
14
6
The MPU CTRL register:
See the register summary in
assignments are:
• enables the MPU
• enables the default memory map background region
• enables use of the MPU when in the hard fault, Non-maskable Interrupt (NMI), and
FAULTMASK escalated handlers.
Reserved
29
21
13
5
28
20
12
4
Table 10-35 on page 197
Reserved
Reserved
Reserved
27
19
11
“Memory model” on page
3
PRIVDEFENA
26
18
10
2
for the MPU CTRL attributes. The bit
54. Any access by privileged
HFNMIENA
SAM3S8/SD8
SAM3S8/SD8
25
17
9
1
ENABLE
24
16
8
0
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