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

Functional Safety Relevant Feature	PIC10FXXX	PIC12/16F1XX	PIC18FXXXX	XMEGA AVR	MEGA AVR	TINY AVR
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	-	-	●	●	●	●

*Class B Safety Software

Legend:
● Available in all devices
○ Available in some devices
- Not Available