Tag Archives: peripheral DMA

Atmel’s AVR UC3: Low power & ease of use

Atmel’s AVR UC3 has popped up in quite a number of use recent cases on Bits & Pieces, so today we will be taking a closer look at the stalwart microcontroller (MCU) family which is built on high-performance 32-bit AVR architecture and optimized for highly integrated applications.

Essentially, the AVR UC3 delivers high computational throughput, deterministic real-time control, low-power consumption, low system cost, high reliability and ease-of-use. As previously discussed on Bits & Pieces, the AVR CPU boasts a plethora of cutting-edge features including integer and fixed point DSP (digital signal processor) arithmetic and single-cycle multiply-accumulate instructions.

Meanwhile, a dual-port SRAM, peripheral DMA (direct memory access) controller and multi-layer, high-speed bus architecture makes the AVR UC3  core ideal for high-throughput applications. As such, AVR UC3  devices are perfectly suited for portable and battery-powered applications due to their optimized low-power properties.

Another important feature of Atmel’s AVR UC3 is picoPower technology, which allows the AVR UC3 to further extend the battery life of portable devices.

“True 1.62V operation means  selected AVR UC3 devices can utilize a 1.8V (± 10%) regulated power supply – with all functions working,” an Atmel engineering rep told Bits & Pieces. “Indeed, picoPower AVR UC3 devices consume only 650nA with the RTC (real time clock) running, enabling ultra-low sleep current combined with fast wake-up for high integrated microcontrollers.”

On the security side, selected AVR UC3 devices provide mechanisms to protect the system from unauthorized modification, flash software theft and runaway code. Atmel’s FlashVault code protection allows CPU resources and sections of code/data memory to be reserved for proprietary software IP or critical sections of code/data, while a special API (application programming interface) is used to access these resources from the rest of the code. Attempts to access these resources by circumventing this API (either by hacking or runaway code) will be aborted and result in an exception.

In terms of the Digital Signal Processor, the 32-bit AVR UC3 offers unrivaled DSP performance compared to legacy architectures.

“By including powerful instructions for single cycle, multiply accumulate and fractional multiply for various number formats, the 32-bit AVR UC3 delivers unrivaled DSP (digital signal processor) performance compared to legacy architectures,” the Atmel engineering rep noted. “In the AVR UC3  software framework more than 70 DSP functions have been assembly optimized utilizing these instructions. In short, DSP has never been easier.”

And last, but certainly not least, Atmel’s peripheral DMA (direct memory access) controller sets a new standard for data transfer efficiency. For example, if the peripheral DMA controller is not enabled, the maximum usable transfer rate on the SPI (serial peripheral interface) module would be approximately 1MBit/s – occupying the CPU with more than 50% load just moving data around. However, with the peripheral DMA controller, this bottleneck is removed and the Atmel AVR UC3 microcontroller can achieve a transfer rate of 33MBit/s on SPI and USART with only a 15% load on the CPU.

“The innovative peripheral event system in the AVR UC3 also represents a paradigm shift, as it allows the AVR UC3 to send signals (events) directly to other peripherals without involving the CPU. This ensures short and predictable response time. At the same time it offloads the CPU and reduces power consumption,” the engineering rep added.

Want to learn more about Atmel’s lineup AVR UC3 MCUs? Be sure to check out our official UC3 page here.