1.2.2 CSM Impact on Other On-Chip Resources
The CSM affects access to the on-chip resources listed in
Table 1-10. Resources Affected by the CSM
Address
Block
0x00 0A80 - 0x00 0A87
Flash Configuration Registers
0x00 8000 - 0x00 87FF
L0 SARAM (2K x 16)
0x00 8800 - 0x00 8BFF
L1 DPSARAM - CLA Data RAM 0 (1K x 16)
0x00 8C00 - 0x00 8FFF
L2 DPSARAM - CLA Data RAM 1 (1K x 16)
0x00 9000 - 0x00 9FFF
L3 DPSARAM - CLA Program RAM (4K x 16)
0x3D 8000 - 0x3F 7FFF or
0x3E 8000 - 0x3F 7FFF
Flash (128K x 16)
Flash (64K x 16)
0x3D 7800 - 0x3D 7BFF
User One-Time Programmable (OTP) (1K x 16)
0x3D 7C00 - 0x3D 7FFF
TI One-Time Programmable (OTP)
(1K x 16)
0x00 A000 - 0x00 BFFF
L4 SARAM
(1)
Not affected by ECSL
The Code Security Module has no impact whatsoever on the following on-chip resources:
• Single-access RAM (SARAM) blocks not designated as secure - These memory blocks can be freely
accessed and code run from them, whether the device is in secure or unsecure mode.
• Boot ROM contents - Visibility to the boot ROM contents is not impacted by the CSM.
• On-chip peripheral registers - The peripheral registers can be initialized by code running from on-chip or
off-chip memory, whether the device is in secure or unsecure mode.
• PIE Vector Table - Vector tables can be read and written regardless of whether the device is in secure or
show which on-chip resources are affected (or are not affected)
by the CSM.
Table 1-11. Resources Not Affected by the CSM
Address
Block
0x00 0000 - 0x00 03FF
M0 SARAM (1K x 16)
0x00 0400 - 0x00 07FF
M1 SARAM (1K x16)
0x00 0800 - 0x00 0CFF
Peripheral Frame 0 (2K x 16)
0x00 0D00 - 0x00 0FFF
PIE Vector RAM (256 x 16)
0x00 6000 - 0x00 6FFF
Peripheral Frame 1 (4K x 16)
0x00 7000 - 0x00 7FFF
Peripheral Frame 2 (4K x 16)
To summarize, it is possible to load code onto the unprotected on-chip program SARAM using the JTAG
connector without any impact from the Code Security Module. The code can be debugged and the peripheral
registers initialized, independent of whether the device is in secure or unsecure mode.
1.2.3 Incorporating Code Security in User Applications
Code security is typically not employed in the development phase of a project; however, security may be desired
once the application code is finalized. Before such a code is programmed in the Flash memory, a password
should be chosen to secure the device. Once a password is in place, the device is secured (that is, programming
a password at the appropriate locations and either performing a device reset or setting the FORCESEC bit
(CSMSCR.15) is the action that secures the device). From that time on, access to debug the contents of secure
memory by any means (by way of JTAG, code running off external/on-chip memory, and so on) requires the
supply of a valid password. A password is not needed to run the code out of secure memory (such as in
end-customer usage); however, access to secure memory contents for debug purpose requires a password.
System Control and Interrupts
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
TMS320x2806x Microcontrollers
55
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
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