Safety and Monitoring
We designed these peripheral and device features to assist in the development of safe and reliable applications. You can also use many of these capabilities create functional safety applications requiring Class B and UL certifications.
Advanced Security
Select PIC® and AVR® product families have enhanced code protection and security features to meet the growing advanced security requirements for consumer Internet of Things (IoT) applications such as household appliances, wearable health trackers, security systems/baby monitors, HVAC systems and countless other applications. These PIC and AVR devices utilize secure elements to improve on-chip security and memory access partitioning to securely protect and store configuration data for the application.
Peripherals and Features
Programming Debugging Interface Disable (PDID)
This function disables the connections to the device’s memory to lock that memory and prevent it from being accessed through the standard programming and debugging interface.
Secure Bootloader
This user-programmable bootloader uses hardware roots of trust to ensure the application’s software integrity at startup. This bootloader also acts as an immutable bootloader when the PDID function is enabled in conjunction with the secure bootloader.
Cyclical Redundancy Check (CRC)
CRC is a powerful technique commonly used to check integrity in digital data. This integrated capability provides a quick and reliable method to verify the integrity of the program memory contents prior to the execution of the application code.
Secure Keys and Authentication
Each application has unique requirements, so we offer a comprehensive portfolio of solutions for implementing trust and security in your design. This will free up time so that you can focus on your application development.
Timer2 with Hardware Limit Timer (HLT)
Timers that can be reset by an external hardware source compare a predefined period value to an incrementing timer counter. When the timer counter reaches the period value, the next action or event is triggered. A timer can be used for core-independent monitoring of an external heartbeat signal or as a secondary watchdog.
Windowed Watchdog Timer (WWDT)
A WWDT acts as a CPU-independent system supervisor that detects abnormal operation of the software. If the software execution takes longer or shorter than expected, the WWDT issues a reset of the MCU to bring the system to a known safe state. A WWDT offers upper and lower time thresholds, while a Watchdog Timer (WDT) offers only a single threshold.
Fail-Safe Clock Monitor (FCS) and Clock Failure Detection (CFD)
All digital ICs depend on a clock to operate and will halt if the clock stops. To ensure the safe operation of an application, it is important to detect whether the MCU's main clock stops. The FCS/CFD detects whether the main clock has stopped and automatically switches to a different clock. This allows the safety software to take appropriate actions such as resetting the MCU to enter into a safe state.
Power-On Reset (POR)
All integrated circuits (ICs) require an absolute minimum supply voltage to operate. The integrated POR circuit holds the microcontroller (MCU) in reset while the supply voltage is below this threshold to ensure that memories, registers and digital and analog circuits are functional at the start-up clock speed. The POR is always combined with a Brown-Out Reset (BOR) circuit.
Brown-Out Reset/Detector (BOR/BOD) and Voltage Level Monitor (VLM)
The integrated BOR/BOD circuit keeps the MCU in reset as long as the supply voltage is below the user-selected threshold to ensure correct operation of the MCU above the start-up clock speed. It is important to use the correct BOR/BOD level as an MCU may fail if operated at a clock speed that exceeds the supply voltage.
Stack Overflow Detection
In the event of software bugs or runaway code, a stack overflow may corrupt other data located next to the stack. The stack monitor helps detect any issues that occur during software development. It also enables the safety software to detect issues in the field and take appropriate actions.