In the first part of this series, we took a closer look at how Atmel’s AVR low-power 32-bit microcontrollers (MCUs) help enable the implementation of various product-differentiating features, including advanced control algorithms, voice control and capacitive touch sensing. In part two, we discussed powering Atmel’s AVR UC3C 32-bit automotive-grade microcontrollers with either a 3.3V or a 5V supply (generally supporting 5V I/O) and focused on Atmel’s Peripheral Event System.
And today we will exploring how Atmel’s low-power 32-bit microcontrollers (MCUs) are used to help protect IP and bolster system safety. Firstly, it is important to note that code protection has become a critical design consideration, as software contains an increasing amount of intellectual property (IP). As such, internal Flash memory should be locked to protect code from being read or copied – with system development significantly accelerated by making application code available from third-party devs in a locked section of the Flash memory.
“Microcontrollers must either be programmed before they are assembled on boards or programmed in-device. Yet, preprogramming creates a challenge in logistics, as devices must be programmed in a trusted facility and transported to the manufacturing site,” an Atmel engineering rep told Bits & Pieces.
“In contrast, programming in-system allows the most recent code to be added during the manufacturing stage or in the field. The AVR UC3C arrives with USB drivers that support the Device Firmware Upgrade (DFU) class to allow devices to be programmed over the system’s USB port. As an alternative, a boot loader can be used to allow in-system programming using the CAN interface.”
And that is precisely why Atmel’s AVR UC3C 32-bit microcontroller architecture includes the Atmel FlashVault code protection technology, which allows the on-chip Flash to be partially programmed and locked, creating secure on-chip storage for software IP and boot loader operation.
On the system safety side, systems must be able to recover quickly from clock failure. Indeed, motor control systems must be able to shut systems down upon detection of clock failure to prevent severe damage to the motor or operator. To achieve this, the UC3C devices incorporate a main clock failure detection functionality that immediately switches over to the internal 115kHz RC oscillator in case of malfunction. The system may either continue operation using the backup clock (while triggering an alarm that the primary clock has failed) or perform any necessary shut-down operation to place the system in a fail-safe condition.
Interested in learning more about 32-bit AVR MCUs for automotive applications? Be sure to check out part four of this series which details how Atmel MCUs can be used to streamline automotive development. Part one can be read here and part two is available here.