Atmel overview

Atmel – microcontrollers, microprocessors, touch controls, ZigBee wireless MCUs and an integrated development environment

Atmel has been at the forefront of microcontroller development for over twenty years. Credited with launching the first Flash-based 8-bit microcontroller, the AVR, in 1996, the RISC architecture AVR family has grown into a comprehensive line-up of 8-bit and 32 bit microcontrollers. The AVR suits a very broad range of applications from wearable devices to industrial automation, and delivers industry-leading power consumption and compute performance. Complementing the AVR family is Atmel’s line-up of ARM based devices, including microcontrollers based on the Cortex-M0+, Cortex-M3 and Cortex-M4, and ARM7 cores. With even more performance Atmel also offers embedded microprocessors that utilise the ARM Cortex-A5 application processor core.


AVR microcontrollers

The portfolio starts with the extremely compact tinyAVR 8-bit MCU that is available with up to 8kB of Flash, operation up to 20 MHz and a performance of 1.0 MIPS/MHz. The smallest of these devices measures only 1.5 x 1.4 mm, and has only 6 pins. Selected devices can operate from as low as 0.7 V thanks to a built-in boost regulator. The series offers ADCs, Flash, EEPROM, Brown-Out detector and a comprehensive I/O, where each pin can have multiple uses, A typical tinyAVR device is the ATTINY20-SSU.

Covering the mid-range is the megaAVR family of devices. More suited to processing larger amounts of code, and with a performance up to 20 MIPS, the 8-bit megaAVR peripheral connectivity includes LCD controllers, and the specialised LIN and CAN serial interfaces. Atmel’s picoPower ultra-low power technology is available on selected models. picoPower’s user-selectable sleep modes are ideal for use with power-constrained battery-powered applications. Available in a 64-pin TQFP package the ATmega645p has 8 x 10-bit ADC, 4 x 16-bit PWM channels and 64kB of Flash memory. Atmel’s ATmega328 device is well known in the maker and hobbyist community as the microcontroller of choice for many of the popular Arduino boards including the Uno, Ethernet, LillyPad, Mini and Nano boards.  The ATmega250 is also used in the Arduino MEGA.

The AVR XMEGA family heads up the highest performance of the 8-bit AVR line-up with an instruction set that supports 16-bit register access and up to 32-bit ALU arithmetic. A key feature of the family is the use of power-saving peripherals, achieved via the device’s highly innovative Peripheral Event System. This is a set of features that allows peripherals to interact without intervention from the CPU. With up to 384kB Flash, fast 12-bit ADCs and Atmel’s ultra-low power saving technology picoPower, the AVR XMEGA has a good balance of memory size, low power consumption and fast wake-up times.

The final member of the AVR family is the UC3 series of 32-bit AVR microcontrollers comprising seven distinct ranges each with specific features such as a floating point unit (FPU), Ethernet support, large SRAM and audio firmware. Equipped with up to 512 KB of Flash, native fixed point DSP support, peripheral DMA controller, together with Atmel’s leading picoPower and Peripheral Event System, makes the UC3 series an extremely efficient 32-bit microcontroller. One example is the AT32UC3C0512C 66 MHz, 512KB device packaged in a LQP144 format. It has dual LIN and CAN interfaces, an FPU and 68 KB of SRAM.


ARM microcontrollers

For those designers that prefer to use an ARM-based microcontroller Atmel offers several options. These include the Flash memory microcontrollers using the Cortex-M0+, M3, M4, M4F, ARM926/ARM9 and ARM7 cores and embedded microprocessors without on-board Flash based on the Cortex-A5 core.

The ARM-based MCUs have up to 2 MB of Flash, up to 160 KB of SRAM and can operate up to 120 MHz. The SAM3U, SAM3N, SAM3A, SAM3S and SAM3X series all use the Cortex-M3 core. Each series offers slightly different configurations of memory, connectivity and features. For example, the SAM3A is optimised for CAN connectivity and suits applications such as industrial control and machine-to-machine. Continuing Atmel’s involvement with Arduino, the SAM3X8E device is used in the Arduino Due board.  Available in 100 and 144-pin packages it is equipped with up to 512KB dual-bank Flash and can operate up to 86 MHz.

The Cortex-M4 core provides the basis of the SAM4L, SAM4E, SAM4G, SAM4N and SAM4S series. Again, each series offers slightly different configurations but all offer uncompromised levels of low power consumption. In particular, the SAM4G is ideal for use in mobile and wearable devices and has a power consumption profile down to 100uA/Mhz in active mode. This series is also equipped with an FPU and up to 512 KB Flash.

The SAMA5D3 is a Cortex-A5 based embedded microprocessor that suits high performance HMI, imaging & industrial designs. With a performance up to 850 DMIPS at 536 MHz, low power consumption down less than 0.5mW, a host of connectivity including TFT LCD & Gigabit Ethernet, and on-chip AES encryption engine, the SAMA5D3 also features Linux support and QuickTime graphics package.


Wireless microcontrollers, transceivers and modules

Well positioned for the need for low power wireless connectivity, especially with the current buzz surrounding the Internet of Things (IoT), Atmel offers a range of 802.15.4-based single-chip wireless microcontrollers, transceivers and pre-certified wireless modules. Supporting the regionally allocated ISM bands of 700, 800 and 900 MHz together with the worldwide 2.4 GHz spectrum, these devices offer engineers design flexibility for incorporating connectivity.

Single-chip 2.4 GHz solutions are available with either an AVR or ARM Cortex-M0+ core. Some models also have an antenna diversity feature that enhances link reliability by automatically switching between two antennas. Transceiver devices, such as the 2.4GHz AT86RF233, provide a low power SPI-to-antenna capability complete with an AES crypto engine that is ideal for consumer applications.

For many designers, achieving wireless regulatory compliance can be a daunting task.  Mindful of this, Atmel has introduced the ZigBits range of pre-qualified 802.15.4 modules that speeds time to market and eases integration. Supplied complete with ZigBee Pro software and an integrated chip antenna, these modules are available in sub-GHz and 2.4 GHz versions. An example is the ATZ-B24-B0R The module has a +3 dBm output power and -101dBm receive sensitivity and is equipped with UART, SPI and I2C interfaces.


Integrated Development Environment

Atmel’s Studio 6.2 provides a free-of-charge, seamless and fully integrated development environment for Atmel’s complete range of AVR and ARM microcontrollers. Whether you choose to develop in C/C++ or assembly, Atmel Studio 6 is the ideal IDE. Atmel’s Software Framework (ASF), integrated into Studio 6, gives developers access to an extensive library of drivers, communication stacks, and graphics functions that are portable across 8- and 32-bit designs. Additional tools such as Atmel QTouch Composer and Wireless Composer seamlessly integrate with Atmel Studio 6 to ease the development of touch controls and wireless connectivity.


Touch controllers

Atmel is also renowned for its leadership in touch sensing controllers. This encompasses simple buttons, wheels and slider controls up to the multiple touchscreen controllers. An example suited to 8 button designs is the Atmel AT42QT1085 an 8-channel touch controller.


Evaluation and development kits

Using an evaluation kit is a perfect way of testing proof of concept or prototyping a new design. If you are considering using a new microcontroller or wireless device, Atmel offers a comprehensive range of evaluation kits on which to validate your design. For example, the ATSAMA5D3-XPLD evaluation board eases ARM Cortex-A5 development. The board features an ATSAMA5D36 application class microprocessor running at 536 MHz, FPU, dual Gigabit Ethernet ports, 256 MB of DDR2 and NAND Flash, in addition to Arduino R3 Shield-compatible expansion headers.

The Xplained Pro Evaluation board provides an extremely low cost method of becoming familiar with the 32-bit ARM Cortex-M4 microcontroller. If considering using the AVR architecture, the AT90USB1287 is an extremely cost effective and convenient way of prototyping 8-bit AVR designs.