SLAU358Q September 2011 – October 2019
The MSP430 family has an option to block access to the MCU through the JTAG and SBW interface. To select the Secure Device option, press the Secure Device Option button on the GUI or select the option from the pulldown menu under Setup→Secure Device. Figure 2-13 shows the Secure Device Options window. When the Secure Device option is selected, the device is secured at the end of the GO programming procedure if all programming steps pass successfully. Otherwise, the device is not secured. For MSP430 devices, the Secure Device process is not reversible.
In some MCUs, typically the FRAM family, a lower JTAG and SBW protection level is available. The JTAG and SBW can be protected by password that is saved in the MCU flash at the addresses 0xFF80 through 0xFFFF. If the password in the code file at this address is the same as the password saved inside the flash, then access to JTAG and SBW is unlocked, and flash can be reprogrammed. This is useful for updating firmware after initial programming.
However, if the device is secured using the Secure Device procedure, then unlocking by using this password is no longer possible. The Secure Device mechanism provides a higher level of protection.
The MSP432 family implements a different approach to memory protection. The MSP432 can provide protection for selected memory regions or to block communication. All protection options are described in the MSP432 technical reference manual and are implemented by programming the flash mailbox (see the MSP432P4xx Family Technical Reference Manual (SLAU356) for details). The MSP-GANG can program the flash mailbox according to user settings or directly from a code file. When the Secure Device Option button is selected for the MSP432 family, the Secure Device Options screen is displayed (see Figure 2-14).
Many types of protection options are available and can be set in the Enabled Commands screen (see Figure 2-15).