Bsl Invocation - Texas Instruments MSPM0 User Manual

www.ti.com
2. Command reception
3.1.1.1 Interface Autodetection
In Interface detection phase, if there is no valid connection command received for 10 seconds over any interface,
the bootloader enters STANDBY mode.
POR is required to get out of this state and use Bootloader by creating the BSL invocation condition again.
3.1.1.2 Command Reception
In command reception phase, if no valid command is received for 10 seconds, the bootloader will enter SLEEP
mode. To wake up the device from SLEEP mode, a data transaction should happen on the active interface.
Bootloader will be locked before entering Sleep mode to reduce attack surface. Hence after waking up from the
low power mode, Bootloader needs to be unlocked again by sending the 256 bit BSL Password (See
Bootloader command ).
Bootloader user LFCLK for the timeout check. If application configures the external clock as the
source for LFCLK, the same will be used by BSL, when invoked through Application BSL request

3.2 BSL Invocation

Bootloader shall be invoked only by the boot code, when any of the BSL invocation conditions is met and if
Bootloader is enabled in BCR configuration TRM.
When Fast boot mode is enabled in BCR configuration, bootloader can be invoked only by Debug mailbox
command and Application request. Other checks are skipped to save execution time.
3.2.1 Blank Device
Bootcode detects the blank device by checking the erase state of the Stack pointer (0x00000000) and reset
vector (0x00000004) address. When both the flash memory addresses are found to be blank, then Bootloader
will be invoked.
3.2.2 Application Request
To invoke the bootloader from an application, set the RESETLEVEL as BOOTLOADERENTRY and trigger reset
through the RESETCMD register. This sequence causes a system reset, and the bootcode is executed and the
bootloader is invoked.
Because a system reset is issued, all the peripheral configurations are reset while exiting the application.
3.2.3 GPIO Based Invocation
GPIO used for BSL invocation can be configured in the BSL Configuration
Fresh devices will have the TI programmed default pin detail in BSL configuration.
GPIO pin based invocation can be disabled in the BCR configuration. It is enabled by default.
GPIO should be asserted before the POR, and the state should be maintained for at-least T_start ms after POR.
Then the GPIO pin state can be de-asserted.
SLAU887 – FEBRUARY 2023
Submit Document Feedback
Note
Copyright © 2023 Texas Instruments Incorporated
BSL Architecture
TRM in Non-main memory.
MSPM0 Bootloader
Unlock
5