13.12 CRC-on-Boot Module Overview

The CRC-on-boot module performs a CRC (Cyclic Redundancy Check) on user-defined segments of nonvolatile memory on device power-up and compares the resulting values to predetermined expected values. This check acts independent of program memory and executes before any user code. If a mismatch occurs, the CRC-on-boot module can be configured to indicate this mismatch in several configurable ways.

The CRC-on-boot has the following features:

• Scanning Program Memory Boot Block
• Scanning Non-Boot Block Nonvolatile Memory
  • Program Memory Application Block
  • Program Memory SAF segment
  • Configuration Words
  • Data EEPROM
• Ability to either halt the device on mismatch or continue to user code execution
• Mismatch indicating the output can be enabled/disabled, relocated and configured as open-drain