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8-Bit MCUs

Functional Safety

Microchip has an ever-expanding offering of solutions for your functional safety needs. Several hardware peripherals and functions have been integrated into our 8-bit PIC® and AVR® portfolios of microcontrollers (MCUs) to help increase the reliability and redundancy for a broad range of applications. The table below describes the hardware modules available on the different families of 8-bit microcontroller devices. System-level monitors are included for POR, BOR, WWDT, Hardware Limit Timer as well as many other fault detection and reliability features.


Microchip has developed a library of low-level software routines that simplify meeting IEC 60730 requirements for Class B Safety. Application notes are available that describe the Application Programming Interface (API) functions and their use that are available in the Class B Safety Software Library for both PIC and AVR microcontrollers.

Hardware Modules

  • Clocking systems including backup oscillators
  • GPIO with ESD protection
  • Power system monitors: POR, BOR, HLVD
  • System monitors: Hardware Limit Timer, WWDT

Software Modules

  • Detect occurrence of faults in a single-channel CPU
  • Developed in accordance with IEC 60730 to support Class B Certification
  • Routines integrate into MCU applications to test and verify critical functionalities without affecting the end application

Whole Ecosystem

  • ISO26262 certified compiler
  • FMEDA report*
  • MPLAB® X IDE MISRA plug-in
  • Affiliation with certification bodies (VDE, UL)
  • Plug-in for code coverage tools by LDRA

Functional Safety Relevant Features for 8-bit PIC and AVR MCUs

Dedicated Core Independent Peripherals and functions have been integrated into the 8-bit PIC and AVR devices to help increase the reliability and monitoring for safety-critical applications. Together these features help ensure end applications operate as intended, with safe shut down if any exception or issue arises.

Memory (Flash / RAM) Error Detection and Correction
-        CRC module
-        Read/write protection
-        Boot segment protection
-        RAM variable memory test
-        Self-readable Flash memory
System Reset, Detect and Manage
-        Power-on and brown-out resets
-        Window watchdog timer
-        Hardware limit timer
-        High/low voltage detect
-        Unique ID
-        Asynchronous master clear reset
-        CAN port loopback mode
GPIO ESD Protection / PPS
-        ESD protection
-        Peripheral Pin Select (PPS)
-        Self-readable output pins
Clocking Systems Backup Oscillators / Monitors
-        Fail safe Clock monitor
-        Frequency detect*
-        Windowed watchdog
-        Hardware Limit timer

*Class B Safety Software function

CPU Trap Instructions / Fault Detection
-        Program counter stuck-at fault*
-        CPU register test*

*Class B Safety Software function

Analog Internal Vref and Sample / Hold
-        Internal voltage reference
-        Zero cross detection module
Other Features
-        C-compiler qualified per ISO-26262
-        LDRA Compliance Management Tool Suite support
Self-Readable Output Pins
Watchdog Timer (WDT) + Internal RC Osc.
Windowed Watchdog Timer (WWDT)-
Asynchronous Master Clear Reset (MCLR)
Under Voltage Detection (BOR, PLVD, HLVD)
Over Voltage Detection (HLVD)-----
Self-Readable Flash Memory
Fail-Safe Clock Mode (FSCM)--
Hardware CRC Engine (RAM/Flash/Data Comm)-
CAN Port Loopback Mode----
Hardware Limit Timer (HLT)--
C-Compiler ASIL-D Qualified per ISO-26262---
LDRA Compliance Management Tool Suite---
Configuration Change Protection--
Sleep Disable---
Hardware Stack Overflow/Underflow Protection----
Interrupt Priority Configuration--
PWM Hardware Shutdown--
● Available in all devices
○ Available in some devices
- Not Available
* Class B Safety Software