SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
MSPM0 MCUs implement a static write protection scheme to lock out the NONMAIN flash region from any program/erase operations at runtime. The write protection scheme is configured as a part of the boot security policies in the NONMAIN flash region.
PurposeBy default, the NONMAIN configuration memory (which contains the user-specified boot security policies and bootstrap loader policies) is not write protected. This enables the NONMAIN to be erased by the user during provisioning and re-programmed with the user-specified policies to use in mass production.
In many cases, it is desirable for the configuration memory to be locked after it has been provisioned. Locking the configuration memory has the benefit of preventing any unauthorized modification of the security policies, bootstrap loader policies, and static write protection policies by either the bootstrap loader or the application code. In most applications, devices in mass production do not require modification of the configuration memory, even when the device firmware is updated.
Capabilities
When configured to be protected, the entire NONMAIN region will be write-locked and will be functionally immutable when the boot configuration routine transfers execution to either the bootstrap loader or the user application code in MAIN flash. Any attempt to program or erase the NONMAIN by the application code or the bootstrap loader will result in a hardware flash operation error, and the sector will not be modified.
While static write protection prevents any modification by application code or the boot loader, a factory reset command sent through the SWD interface would still be honored. If this behavior is not desired, the factory reset SWD command may be protected with a unique password or disabled altogether (see the SWD policies). To completely remove any means of modifying the NONMAIN configuration memory, the factory reset command and TI FA (or the SW-DP) must be disabled.