TCI6630K2L Datasheet, PDF (16/298 Pages) Texas Instruments – Multicore DSP+ARM KeyStone II System-on-Chip

TCI6630K2L
SPRS893E – MAY 2013 – REVISED JANUARY 2015
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4.1.4 Multicore Shared Memory SRAM
The MSM SRAM configuration for the TCI6630K2L device is as follows:
• Memory size of 2048KB
• Can be configured as shared L2 or shared L3 memory
• Allows extension of external addresses from 2GB up to 8GB
• Has built-in memory protection features
The MSM SRAM is always configured as all SRAM. When configured as a shared L2, its contents can be
cached in L1P and L1D. When configured in shared L3 mode, it’s contents can be cached in L2 also. For
more details on external memory address extension and memory protection features, see the KeyStone
Architecture Multicore Shared Memory Controller (MSMC) User's Guide (SPRUGW7).
4.1.5 L3 Memory
The L3 ROM on the device is 128KB. The ROM contains software used to boot the device. There is no
requirement to block accesses from this portion to the ROM.
4.2 Memory Protection
Memory protection allows an operating system to define who or what is authorized to access L1D, L1P,
and L2 memory. To accomplish this, the L1D, L1P, and L2 memories are divided into pages. There are 16
pages of L1P (2KB each), 16 pages of L1D (2KB each), and 32 pages of L2 (32KB each). The L1D, L1P,
and L2 memory controllers in the C66x CorePac are equipped with a set of registers that specify the
permissions for each memory page.
Each page may be assigned with fully orthogonal user and supervisor read, write, and execute
permissions. In addition, a page may be marked as either (or both) locally accessible or globally
accessible. A local access is a direct DSP access to L1D, L1P, and L2, while a global access is initiated
by a DMA (either IDMA or the EDMA3) or by other system masters. Note that EDMA or IDMA transfers
programmed by the DSP count as global accesses. On a secure device, pages can be restricted to secure
access only (default) or opened up for public, non-secure access.
The DSP and each of the system masters on the device are all assigned a privilege ID. It is possible to
specify only whether memory pages are locally or globally accessible.
The AIDx and LOCAL bits of the memory protection page attribute registers specify the memory page
protection scheme, see Table 4-1.
Table 4-1. Available Memory Page Protection Schemes
AIDx BIT⁽¹⁾ LOCAL BIT DESCRIPTION
0
0
No access to memory page is permitted.
0
1
Only direct access by DSP is permitted.
1
0
Only accesses by system masters and IDMA are permitted (includes EDMA and IDMA accesses initiated by
the DSP).
1
1
All accesses permitted.
(1) x = 0, 1, 2, 3, 4, 5
Faults are handled by software in an interrupt (or an exception, programmable within the CorePac
interrupt controller) service routine. A DSP or DMA access to a page without the proper permissions will:
• Block the access — reads return 0, writes are ignored
• Capture the initiator in a status register — ID, address, and access type are stored
• Signal the event to the DSP interrupt controller
The software is responsible for taking corrective action to respond to the event and resetting the error
status in the memory controller. For more information on memory protection for L1D, L1P, and L2, see the
TMS320C66x DSP CorePac User's Guide (SPRUGW0).
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C66x CorePac
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