ATXMEGA128B1 Datasheet, PDF (4/138 Pages) ATMEL Corporation – 8/16-bit Atmel XMEGA B1 Microcontroller

3. Overview
The Atmel^® AVR^® XMEGA^® is a family of low power, high performance, and peripheral rich 8/16-bit microcontrollers
based on the AVR enhanced RISC architecture. By executing instructions in a single clock cycle, the Atmel AVR XMEGA
devices achieve CPU throughput approaching one million instructions per second (MIPS) per megahertz, allowing the
system designer to optimize power consumption versus processing speed.
The AVR CPU combines a rich instruction set with 32 general purpose working registers. All 32 registers are directly
connected to the arithmetic logic unit (ALU), allowing two independent registers to be accessed in a single instruction,
executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs many times
faster than conventional single-accumulator or CISC based microcontrollers.
The Atmel AVR XMEGA B1 devices provide the following features: in-system programmable flash with read-while-write
capabilities; internal EEPROM and SRAM; two-channel DMA controller, four-channel event system and programmable
multilevel interrupt controller, 53 general purpose I/O lines, real-time counter (RTC); Liquid Crystal Display supporting up
to 4x40 segment driver, ASCII character mapping and built-in contrast control (LCD); three flexible, 16-bit timer/counters
with compare and PWM channels; two USARTs; one two-wire serial interface (TWI); one full speed USB 2.0 interface;
one serial peripheral interface (SPI); AES and DES cryptographic engine; two 8-channel, 12-bit ADCs with
programmable gain; four analog comparators (ACs) with window mode; programmable watchdog timer with separate
internal oscillator; accurate internal oscillators with PLL and prescaler; and programmable brown-out detection.
The program and debug interface (PDI), a fast, two-pin interface for programming and debugging, is available. The
devices also have an IEEE std. 1149.1 compliant JTAG interface, and this can also be used for on-chip debug and
programming.
The ATx devices have five software selectable power saving modes. The idle mode stops the CPU while allowing the
SRAM, DMA controller, event system, interrupt controller, and all peripherals to continue functioning. The power-down
mode saves the SRAM and register contents, but stops the oscillators, disabling all other functions until the next TWI,
USB resume, or pin-change interrupt, or reset. In power-save mode, the asynchronous real-time counter continues to
run, allowing the application to maintain a timer base while the rest of the device is sleeping. In power-save mode, the
LCD controller is allowed to refresh data to the panel. In standby mode, the external crystal oscillator keeps running while
the rest of the device is sleeping. This allows very fast startup from the external crystal, combined with low power
consumption. In extended standby mode, both the main oscillator and the asynchronous timer continue to run, and the
LCD controller is allowed to refresh data to the panel. To further reduce power consumption, the peripheral clock to each
individual peripheral can optionally be stopped in active mode and idle sleep mode.
Atmel offers a free QTouch^® library for embedding capacitive touch buttons, sliders and wheels functionality into AVR
microcontrollers.
The devices are manufactured using Atmel high-density, nonvolatile memory technology. The program flash memory can
be reprogrammed in-system through the PDI or JTAG interfaces. A boot loader running in the device can use any
interface to download the application program to the flash memory. The boot loader software in the boot flash section will
continue to run while the application flash section is updated, providing true read-while-write operation. By combining an
8/16-bit RISC CPU with in-system, self-programmable flash, the Atmel XMEGA B1 is a powerful microcontroller family
that provides a highly flexible and cost effective solution for many embedded applications.
The atmel AVR ATx devices are supported with a full suite of program and system development tools, including C
compilers, macro assemblers, program debugger/simulators, programmers, and evaluation kits.
XMEGA B1 [DATASHEET]
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8330C–AVR–07/2012