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C66x CorePac
Copyright 2012 Texas Instruments Incorporated
SPRS689D—March 2012
Multicore Fixed and Floating-Point System-on-Chip
TMS320C6670
Global addresses that are accessible to all masters in the system are in all memory local to the processors. In addition,
local memory can be accessed directly by the associated processor through aliased addresses, where the eight MSBs
are masked to 0. The aliasing is handled within the CorePac and allows for common code to be run unmodified on
multiple cores. For example, address location 0x10800000 is the global base address for CorePac0's L2 memory.
CorePac0 can access this location by either using 0x10800000 or 0x00800000. Any other master on the device must
use 0x10800000 only. Conversely, 0x00800000 can by used by any of the four CorePacs as their own L2 base
addresses. For CorePac0, as mentioned, this is equivalent to 0x10800000, for CorePac1 this is equivalent to
0x11800000, and for CorePac2 this is equivalent to 0x12800000. Local addresses should be used only for shared code
or data, allowing a single image to be included in memory. Any code/data targeted to a specific core, or a memory
region allocated during run-time by a particular CorePac should always use the global address only.
5.1.4 MSM SRAM
The MSM SRAM configuration for the C6670 device is as follows:
•
Memory size is 2048KB
•
The MSM can be configured as shared L2 or shared L3 memory
•
Allows extension of external addresses from 2GB to 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
Multicore Shared Memory Controller
(MSMC) for KeyStone Devices User Guide
2.9 ‘‘Related Documentation from Texas Instruments’’ on page 66
.
5.1.5 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.
5.2 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 only possible to specify
whether memory pages are locally or globally accessible.
Summary of Contents for TMS320C6670
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