7.6.2 Initial Instructions Fetching
After reset is released, the CPU starts fetching from the Boot ROM.
Unless a debugger is connected and places the Boot ROM in a specific
mode called Boot Interactive mode, the CPU will jump to the base address of BFM, loading
the Program Counter (PC) and Stack Pointer (SP) values and subsequently vectoring to the
application entry point address. During start-up, the Boot ROM initializes a portion of
DTCM to facilitate function and optionally initializes the entire compliment of SRAM
based on the setting of the RAM_INIT_ENB configuration fuse bit. The Clocks remain
unchanged.
Note: The PIC32CZ CA Boot Interactive mode allows a debugger
to perform several actions on the device, such as NVM areas integrity check, chip
erase, and so on. Refer to the “Boot ROM” section for more information.
In addition, the PIC32CZ CA Boot ROM has extra security features, such as device integrity checks, memories and peripherals security attributions, and secure boot that can be executed before jumping to the Flash in Secure state.