MPU Registers
110
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Memory Protection Unit (MPU)
5.3.10 Programmable Range n Start Address Registers (PROGn_MPSAR)
NOTE:
In some cases the amount of physical memory in actual use may be less than the maximum
amount of memory supported by the device. For example, the device may support a total of
512 Mbytes of SDRAM memory, but your design may only populate 128 Mbytes. In such
cases, the unpopulated memory range must be protected in order to prevent
unintended/disallowed aliased access to protected memory, especially memory. One of the
programmable address ranges could be used to detect accesses to this unpopulated
memory.
The programmable range
n
start address register (PROG
n
_MPSAR) holds the start address for the range
n
. The PROG
n
_MPSAR is writeable by a supervisor entity only.
The start address must be aligned on a page boundary. The size of the page depends on the MPU: the
page size for MPU1 is 1 KBbyte; the page size for MPU2 is 64 KBytes. The size of the page determines
the width of the address field in PROG
n
_MPSAR and the programmable range
n
end address register
(PROG
n
_MPEAR). For example, to protect a 64-KB page starting at byte address 8001 0000h, write
8001 0000h to PROG
n
_MPSAR and 8001 FFFFh to PROG
n
_MPEAR.
5.3.10.1 MPU1 Programmable Range n Start Address Register (PROG1_MPSAR-PROG6_MPSAR)
The PROG
n
_MPSAR for MPU1 is shown in
and described in
Figure 5-12. MPU1 Programmable Range n Start Address Register (PROGn_MPSAR)
31
10
9
0
START_ADDR
Reserved
R/W-20 0000h
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 5-15. MPU1 Programmable Range n Start Address Register (PROGn_MPSAR)
Field Descriptions
Bit
Field
Value
Description
31-10
START_ADDR
20 0000h–
20 007Fh
Start address for range N .
9-0
Reserved
0
Reserved
5.3.10.2 MPU2 Programmable Range n Start Address Register (PROG1_MPSAR-PROG12_MPSAR)
The PROG
n
_MPSAR for MPU2 is shown in
and described in
Figure 5-13. MPU2 Programmable Range n Start Address Register (PROGn_MPSAR)
31
16 15
0
START_ADDR
Reserved
R/W-C000h
R-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 5-16. MPU2 Programmable Range n Start Address Register (PROGn_MPSAR)
Field Descriptions
Bit
Field
Value
Description
31-16
START_ADDR
C000h–DFFFh
Start address for range N.
15-0
Reserved
0
Reserved