Most microcontroller vendors are building on Arm’s Cortex-M0+ architecture. It’s the smallest and lowest-power core Arm has, but it’s still just a core. Microcontrollers need a lot more hardware. Atmel’s SAM D20 family, based on Arm’s Cortex-M0+, targets the entire low-end space currently handled by 8- and 16-bit microcontrollers (see the figure). Of course, it hits the low-end 32-bit space as well.
The SAM D20 incorporates high-end support like the high-speed bus matrix linked to three AHB/APB bridges. System and power controllers can be found off one bridge. Memory controllers are found off another. The third bridge handles the convention interfaces that include up to six programmable serial ports, eight timers, a 20-channel, 350-ksample/s analog-to-digital converter (ADC), a pair of comparators, and a 10-bit, 350-ksample/s digital-to-analog converter (DAC). There is also Atmel’s touch interface controller.
Atmel looks to offload the processor with its event system, which allows peripheral events to trigger actions without processor intervention (see “Offloading CPU Boosts Microcontroller Performance And Cuts Power”). The core can actually be sleeping. Also, memory shouldn’t be an issue. The family supports up to 32 kbytes for RAM and 256 kbytes of flash memory.
Atmel is already known for its microcontroller families, including the 8-bit AVR. The SAM D20 will follow in the pin steps of these chips with 32-, 48-, and 64-pin versions that match the SAM4L family.
Atmel’s Studio 6 integrated development environment (IDE) is based on Microsoft’s Visual Studio (see “Visual Studio-based IDE Targets AVR Microcontrollers”). It provides advanced editing capabilities, but it’s designed to only support Atmel’s product family. It also supports the Atmel Software Framework (ASF) with a project wizard that has a collection of over 2000 examples. It also includes protocol stacks and peripheral driver support. And, it works with the Atmel SAM D20 Xplained Pro board (Fig. 2), which supports pluggable expansion.