16.2 Features

The Boot ROM in the PIC32CM device family includes several built-in features to support reliable booting.

• Device Integrity Check: Verifies the authenticity and integrity of the boot image.
• Boot Source Selection: Determines the boot source based on fuse settings and configuration.
• Device Lock down: Supports complete device lockdown, preventing any external read/write access.
• Boot Failure Indication: Asserts a configurable user I/O pin if boot fails when fault signaling is enabled via the BOOTCFG1/1A fuse (BOOT_GPIOSEL).
• Boot Interactive Mode: Allows access to maintenance operations (e.g., CFM integrity check, chip erase) when a debugger probe is connected.
• Debug Access and Security: To maintain a secure boot process, the Boot ROM disables all debug access during its execution.
• Clock Configuration: During Boot ROM execution, the device clocks remain unchanged and operate at their default values. The Boot ROM does not modify the clock configuration.