Atmel Introduces Industry's First ARM Cortex-M3 Flash MCU With On-Chip High Speed USB Device-and-Transceiver

It features 23 DMA channels and distributed on-chip memory including up to 52k Bytes of SRAM split in three blocks and up to 256k Bytes of Flash in two banks. The dual bank Flash offers in-application programming (IAP) where one memory bank is written with a new version of the firmware while the processor executes from the other bank. A programmable boot feature enables switching between the two Flash banks at the next MCU reboot.

Additional features include an 8-channel each 10- and 12-bit ADC, the latter with integrated Programmable Gain Amplifier (PGA), differential and single ended input to remove external OpAmps and a one Msps sample rate, 4 UARTs, 5 SPI, 2 I2C, I2S, timers, PWM, 128-bit unique ID, and power and reset management. The External Bus Interface offers the choice between 8- and 16-bit data bus widths for extended memory or connection to external FPGAs and ASSPs. The SAM3U's supply voltage ranges from 1.62V to 3.6V, a feature not commonly found on Cortex-M3-based MCUs.

Power optimization - The SAM3U incorporates a sophisticated power management regime that minimizes power consumption under all conditions of use. The device can be put in Backup mode with the core and peripherals powered down, in which power consumption is only 2.5 uA. Wake-up from backup mode can be triggered by multiple sources and is accelerated via a high speed on-chip RC Oscillator reducing the average power consumption critical for battery operated systems.

Code portability between SAM7 and SAM3 MCUs - The Cortex-M3 core has a new instruction set architecture, Thumb2. Atmel has taken steps to ensure maximum code portability between its ARM7-, ARM9- and Cortex-M3-based microcontrollers. Its SAM7, SAM9 and Cortex-M3-based SAM3 MCUs have identical hardware abstraction layers and a unified programming model, as well as common peripherals that provide near-recompile-and-go code portability between devices.

Comprehensive support eco-system - Atmel's SAM3U flash MCU is supported by a rapidly growing number of development tools, real-time operating systems (RTOS), middleware products and technical support services from industry-leading third parties that include IAR(R), Keil(R), Micrium(R), and Segger(R). Atmel provides a software package with register descriptions and device drivers for all peripherals, along with project examples that ease the use of the microcontroller. The SAM3U Evaluation Kit is available for benchmarking and a quick start in application development. Availability and Pricing - The AT91SAM3U is available in Flash memory densities of 64k, 128k and 256k Bytes and ships in 100 and 144 pin 0.5mm pitch QFP and 0.8 mm pitch BGA packages. The device is in volume production, with prices starting at US$3.50 in quantities of 10k units.

The block diagram of the SAM3U

An interesting feature is the low voltage operation down to 1.62 Volt, it enables low power operation as well as long battery life. Although analog parts on the MCU will need a higher voltage to operate, the ADCs have a min analog supply voltage of 2.4V, this low voltage operation will use the full life span of 2 rechargeable batteries. Another nice touch and a competitive advantage is the differential input option for the ADC. Most competing devices allow single ended only. Last but not least, the number of serial interfaces marks the upper end of the Cortex-M3 range and will open up some applications other devices can't touch.  

Derivatives include the 100-pin devices SAM3U1E, SAM3U2E, SAM3U4E as well as the 144-pin devices SAM3U1C, SAM3U2C, SAM3U4C

A summary sheet for the ATSAM3U Series is here for download (1.4 MB 57 pages)

The reference manual, complete datasheet, users manual or programmers manual for the ATSAM3U Series, however you want to call is here (21.6MB 1120 pages)

More about Cortex-M3 devices that have been recently announced and compete with the SAM3U

Training for Cortex-M3 including CMSIS software standard through Doulos