Texas Instruments TMS320C6745 DSP - Device Master Settings; Memory Protection Ranges

www.ti.com Architecture
85
SPRUH91D–March 2013–Revised September 2016
Submit Documentation Feedback
Copyright © 2013–2016, Texas Instruments Incorporated
Memory Protection Unit (MPU)
(1)
This peripheral is not supported on the C6745 DSP.
Table 5-3. Device Master Settings
Master Privilege ID Privilege Level Access Type
EDMA3CC Inherited Inherited DMA
EDMA3TC0 and TC1 Inherited Inherited DMA
DSP 1 Software dependant Software dependant
PRU0/PRU1 2 Supervisor DMA
HPI
(1)
3 User DMA
EMAC 4 Supervisor Data/DMA
USB1.1
(1)
5 Supervisor DMA
USB2.0 6 Supervisor DMA
LCD Controller
(1)
7 Supervisor DMA
5.2.2 Memory Protection Ranges
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. One of the programmable
address ranges could be used to detect accesses to this “unpopulated” memory.
The MPU divides its assigned memory into address ranges. Each MPU can support one fixed address
range and multiple programmable address ranges. The fixed address range is configured to an exact
address. The programmable address range allows software to program the start and end addresses.
Each address range has the following set of registers:
• Range start and end address registers (MPSAR and MPEAR): Specifies the starting and ending
address of the address range.
• Memory protection page attribute register (MPPA): Use to program the permission settings of the
address range.
It is allowed to configure ranges such that they overlap each other. In this case, all the overlapped ranges
must allow the access, otherwise the access is not allowed. The final permissions given to the access are
the lowest of each type of permission from any hit range.
Addresses not covered by a range are either allowed or disallowed based on the configuration of the
MPU. The MPU can be configured for “assumed allowed” or “assumed disallowed” mode as dictated by
the ASSUME_ALLOWED bit in the configuration register (CONFIG).