Program
counter
IBL
IBH
<
>=
Memory
address
<
>=
No JTAG or
DMA access
No CPU access
MPU Segments
315
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Memory Protection Unit (MPU)
An unauthorized access to the IPE-segment returns a value equivalent to the instruction "JMP $" and
triggers an interrupt. In addition, the generation of a PUC can be configured.
Table 9-2. IP Encapsulation Access Rights
IBL
≤
Memory Address
< IBH
IBL
≤
Program Counter
< IBH
JTAG or DMA Access
CPU Access
0FF80h
≤
Memory
Address < 0FFFFh
–
Read/Write
Read/Write
False
False
Yes
Yes
False
True
Yes
Yes
True
False
No
No
True
True
No
Yes
Figure 9-6. IP Encapsulation Access Rights Equivalent Schematic
NOTE:
IP Encapsulation area access rights do not override MPU segment rights. The IP
Encapsulation rights are evaluated and if the access is granted, access rights as describe in
are applied.
NOTE:
Code fetch from the first 8 bytes in IPE-segment does not enable data access.
The first 8 bytes within the IPE-segment do not enable data access within the IPE-segment if
code is executed from that area. The start of an IPE-segment is reserved for a data structure
describing the IPE-segment boundaries.
shows the segmentation of the main memory.
9.2.3 Segment Border Setting
describes the procedure of setting borders for segmentation of the main memory. This
section describes how the values in MPUSEGBx[15:0] and MPUIPSEGBx[15:0] bits need to be set to
achieve the desired borders for different memory sizes. The bits of the MUSBx[15:0] bits represent the 16
most significant bits of the border address that can be selected.
The setting of the MPUSEGBx[15:0] bits forms a border between two segments of main memory space.
For the following examples, the segment with the higher address range formed by this border is called the
higher segment. The segment with the lower address range is called the lower segment.