The bootloader supports hardware invocation after a BOOTRST through the use of a GPIO. The BSL configuration in the NONMAIN flash memory contains the pad, pin, and polarity definition for the GPIO invocation. Devices come configured from TI for a specific GPIO and polarity, but software can change this default by modifying the GPIO pin configuration in the BSL configuration in NONMAIN flash memory. See the device specific data sheet to
determine the default BSL invoke GPIO.
Figure 10-1 shows an example for the GPIO pin PA18 with high level to trigger bootloader.