Ameba-D User Manual
User Manual All information provided in this document is subject to legal disclaimers. © REALTEK 2019. All rights reserved.
30
0: MPU is disabled for these handlers.
1: MPU is enabled for these handlers.
Note:
If this bit is set to 1 when ENABLE is set to 0, behavior is unpredictable.
If no MPU regions are implemented, this bit is reserved.
This bit resets to 0 on a Warm reset.
0
ENABLE
R/W
Enable. Enables the MPU.
0: The MPU is disabled.
1: The MPU is enabled.
Disabling the MPU means that privileged and unprivileged accesses use the default memory map.
Note:
If no MPU regions are implemented, this bit is reserved.
This bit resets to 0 on a Warm reset.
3.2.3
MPU_RNR
The MPU_RNR characteristics are:
Purpose:
Selects the region currently accessed by MPU_RBAR and MPU_RLAR.
Usage constraints:
Privileged access is permitted only. Unprivileged access generates a BusFault.
This register is word accessible only. Half-word and byte accesses are unpredictable.
Configurations:
This register is always implemented.
Attributes:
32-bit read/write register located at 0xE000_ED98.
Secure software can access the Non-Secure view of this register via MPU_RNR_NS located at 0xE002_ED98. The location
0xE002_ED98 is reserved to software executing in Non-Secure state and the debugger.
This register is banked between security states.
31
30
29
…
10
9
8
7
6
5
…
2
1
0
RSVD
REGION
R/W
Bit
Name
Access
Description
31:8
RSVD
N/A
Reserved
7:0
REGION
R/W
Region number. Indicates the memory region accessed by MPU_RBAR and MPU_RLAR.
Note:
If no MPU regions are implemented, this field is reserved.
Writing a value corresponding to an unimplemented region is constrained unpredictable.
This field resets to an unknown value on a Warm reset.
3.2.4
MPU_RBAR
The MPU_RBAR register characteristics are:
Purpose
: Provides indirect read and write access to the base address of the currently selected MPU region for the selected security state.
Usage constraints
:
Privileged access is permitted only. Unprivileged access generates a BusFault.
This register is word accessible only. Half-word and byte accesses are unpredictable.
Configurations
: This register is always implemented.
Attributes
:
32-bit read/write register located at 0xE000_ED9C.
Secure software can access the Non-Secure view of this register via MPU_RBAR_NS located at 0xE002_ED9C. The location
0xE002_ED9C is reserved to software executing in Non-Secure state and the debugger.
This register is banked between security states.
Preface
: This register provides access to the configuration of the MPU region selected by MPU_RNR.REGION for the appropriate security
state. The field description applies to the currently selected region.