ATSAM3U4/2/1 Description
Atmels SAM3U series is a member of a family of Flash microcontrollers based on the high performance 32-bit ARM Cortex-M3 RISC processor. It operates at a maximum speed of 96 MHz and features up to 256 Kbytes of Flash and up to 52 Kbytes of SRAM. The peripheral set includes a High Speed USB Device port with embedded transceiver, a High Speed MCI for SDIO/SD/MMC, an External Bus Interface with NAND Flash controller, up to 4xUSARTs (SAM3U1C/2C/4C have 3), up to 2xTWIs (SAM3U1C/2C/4C have 1), up to 5xSPIs SAM3U1C/2C/4C have 4), as well as 4xPWM timers, 3xgeneral purpose 16-bit timers, an RTC, a 12-bit ADC and a 10-bit ADC.

Features
• Core
    – ARM® Cortex®-M3 revision 2.0 running at up to 96 MHz
    – Memory Protection Unit (MPU)
    – Thumb®-2 instruction set
• Memories
    – From 64 to 256 Kbytes embedded Flash, 128-bit wide access, memory accelerator, dual bank
    – From 16 to 48 Kbytes embedded SRAM with dual banks
    – 16 Kbytes ROM with embedded bootloader routines (UART, USB) and IAP routines
    – Static Memory Controller (SMC): SRAM, NOR, NAND support. NAND Flash controller with 4 Kbytes RAM buffer and ECC
• System
    – Embedded voltage regulator for single supply operation
    – POR, BOD and Watchdog for safe reset
    – Quartz or resonator oscillators: 3 to 20 MHz main and optional low power 32.768 kHz for RTC or device clock.
    – High precision 8/12 MHz factory trimmed internal RC oscillator with 4 MHz Default Frequency for fast device startup
    – Slow Clock Internal RC oscillator as permanent clock for device clock in low power mode
    – One PLL for device clock and one dedicated PLL for USB 2.0 High Speed Device
    – Up to 17 peripheral DMA (PDC) channels and 4-channel central DMA
• Low Power Modes
    – Sleep and Backup modes, down to 2.5 µA in Backup mode
    – Backup domain: VDDBU pin, RTC, 32 backup registers
    – Ultra low power RTC: 0.6 µA
• Peripherals
    – USB 2.0 Device: 480 Mbps, 4-kbyte FIFO, up to 7 bidirectional Endpoints, dedicated DMA
    – Up to 4 USARTs (ISO7816, IrDA®, Flow Control, SPI, Manchester support) and one UART
    – Up to 2 TWI (I2C compatible), 1 SPI, 1 SSC (I2S), 1 HSMCI (SDIO/SD/MMC)
    – 3-Channel 16-bit Timer/Counter (TC) for capture, compare and PWM
    – 4-channel 16-bit PWM (PWMC)
    – 32-bit Real Time Timer (RTT) and RTC with calendar and alarm features
    – 8-channel 12-bit 1MSPS ADC with differential input mode and programmable gain stage, 8-channel 10-bit ADC
• I/O
    – Up to 96 I/O lines with external interrupt capability (edge or level sensitivity), debouncing, glitch filtering and on-die Series Resistor Termination
    – Three 32-bit Parallel Input/Outputs (PIO)
• Packages
    – 100-lead LQFP, 14 x 14 mm, pitch 0.5 mm
    – 100-ball TFBGA, 9 x 9 mm, pitch 0.8 mm
    – 144-lead LQFP, 20 x 20 mm, pitch 0.5 mm
    – 144-ball LFBGA, 10 x 10 mm, pitch 0.8 mm