SLAA834B May 2018 – August 2021 MSP430FR2000 , MSP430FR2032 , MSP430FR2033 , MSP430FR2100 , MSP430FR2110 , MSP430FR2111 , MSP430FR2153 , MSP430FR2155 , MSP430FR2310 , MSP430FR2311 , MSP430FR2353 , MSP430FR2355 , MSP430FR2422 , MSP430FR2433 , MSP430FR2475 , MSP430FR2476 , MSP430FR2512 , MSP430FR2522 , MSP430FR2532 , MSP430FR2533 , MSP430FR2632 , MSP430FR2633 , MSP430FR2672 , MSP430FR2673 , MSP430FR2675 , MSP430FR2676 , MSP430FR4131 , MSP430FR4132 , MSP430FR4133 , MSP430FR5720 , MSP430FR5721 , MSP430FR5722 , MSP430FR5723 , MSP430FR5724 , MSP430FR5725 , MSP430FR5726 , MSP430FR5727 , MSP430FR5728 , MSP430FR5729 , MSP430FR5730 , MSP430FR5731 , MSP430FR5732 , MSP430FR5733 , MSP430FR5734 , MSP430FR5735 , MSP430FR5736 , MSP430FR5737 , MSP430FR5738 , MSP430FR5739 , MSP430FR5847 , MSP430FR58471 , MSP430FR5848 , MSP430FR5849 , MSP430FR5857 , MSP430FR5858 , MSP430FR5859 , MSP430FR5867 , MSP430FR58671 , MSP430FR5868 , MSP430FR5869 , MSP430FR5870 , MSP430FR5872 , MSP430FR58721 , MSP430FR5887 , MSP430FR5888 , MSP430FR5889 , MSP430FR58891 , MSP430FR5922 , MSP430FR59221 , MSP430FR5947 , MSP430FR59471 , MSP430FR5948 , MSP430FR5949 , MSP430FR5957 , MSP430FR5958 , MSP430FR5959 , MSP430FR5962 , MSP430FR5964 , MSP430FR5967 , MSP430FR5968 , MSP430FR5969 , MSP430FR59691 , MSP430FR5970 , MSP430FR5972 , MSP430FR59721 , MSP430FR5986 , MSP430FR5987 , MSP430FR5988 , MSP430FR5989 , MSP430FR59891 , MSP430FR5992 , MSP430FR5994 , MSP430FR59941
On the FR4xx devices, the JTAG/SBW is locked by programming a specific signature into the device's FRAM memory at JTAG/SBW signature address of FF80h to FF83h.
When JTAG/SBW is locked by programming the JTAG/SBW signature, access to the device is only possible through the BSL (using the BSL password). However, when the BSL is not disabled and the BSL password is supplied, it is possible to clear the JTAG/SBW signature and make JTAG communication available again. Hence, on the FR4xx devices, locking the JTAG/SBW is reversible if the BSL password is known and BSL is not disabled.
Table 3-2 describes the FR4xx device password, BSL signature, and JTAG/SBW signature.
Name | Address | Value | Device Security | BSL or SBW Behavior After Reset |
---|---|---|---|---|
Device password | FFE0h to FFFFh | Depending on vector table configuration | The value is used to protect BSL. | |
BSL signature | FF84h to FF87h | 5555_5555h | Secured, password not required | BSL is bypassed. User code starts immediately. |
Any other values | Secured, password required through the BSL | BSL is invoked before user code starts if BSL is triggered. | ||
JTAG/SBW signature | FF80h to FF83h | FFFF_FFFFh | Not secured | JTAG/SBW is not locked. |
0000_0000h | ||||
Any other values | Secured | JTAG/SBW is locked. |
On the FR59xx devices, a fuse is used. Securing the device involves writing a specific signature to the JTAG signature location. When the fuse is programmed, access to the device is possible only through the BSL (using the BSL password). However, when the BSL password is supplied, it is possible to clear the JTAG fuse and make JTAG communication available again. Hence, on the FR59xx devices, blowing the JTAG fuse is reversible if the BSL password is known. The FR59xx family also provides an addition feature: JTAG lock with password. The password is located at FRAM location 0xFF88 and can be one to four words in length. To be able to access JTAG, the tool chain needs to first provide the password, following which JTAG access is granted. Any access with an incorrect password prevents JTAG access. When a password is verified, complete JTAG access is possible until the next BOR event.