Atmel SAM4S-EK2 Atmel ATSAM4S-EK2 ATSAM4S-EK2 Ficha De Dados
Códigos do produto
ATSAM4S-EK2
222
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
12.11.2.2MPU Control Register
Name:
MPU_CTRL
Access: Read-write
Reset: 0x00000800
The MPU CTRL register enables the MPU, enables the default memory map background region, and enables the use of the MPU
when in the hard fault, Non-maskable Interrupt (NMI), and FAULTMASK escalated handlers.
when in the hard fault, Non-maskable Interrupt (NMI), and FAULTMASK escalated handlers.
• PRIVDEFENA: Privileged Default Memory Map Enabled
Enables privileged software access to the default memory map:
0: If the MPU is enabled, disables the use of the default memory map. Any memory access to a location not covered by any
enabled region causes a fault.
enabled region causes a fault.
1: If the MPU is enabled, enables the use of the default memory map as a background region for privileged software accesses.
When enabled, the background region acts as a region number -1. Any region that is defined and enabled has priority over this
default map.
default map.
If the MPU is disabled, the processor ignores this bit.
• HFNMIENA: Hard Fault and NMI Enabled
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
. Any access by privileged
software that does not address an enabled memory region behaves as defined by the default memory map.
• Any access by unprivileged software that does not address an enabled memory region causes a memory management
fault.
XN and Strongly-ordered rules always apply to the System Control Space regardless of the value of the ENABLE bit.
31
30
29
28
27
26
25
24
–
23
22
21
20
19
18
17
16
–
15
14
13
12
11
10
9
8
–
7
6
5
4
3
2
1
0
–
PRIVDEFENA
HFNMIENA
ENABLE