Datasheet

4
8493A–AVR–02/12
XMEGA C4
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 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 reg-
isters 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 conven-
tional single-accumulator or CISC based microcontrollers.
The XMEGA C4 devices provide the following features: in-system programmable flash with
read-while-write capabilities; internal EEPROM and SRAM; four-channel event system and pro-
grammable multilevel interrupt controller, 34 general purpose I/O lines, 16-bit real-time counter
(RTC); four, 16-bit timer/counters with compare and PWM channels; three USARTs; two two-
wire serial interfaces (TWIs); one full speed USB 2.0 interface; two serial peripheral interfaces
(SPIs); one sixteen-channel, 12-bit ADC with programmable gain; two analog comparators
(ACs) with window mode; programmable watchdog timer with separate internal oscillator; accu-
rate 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 debug-
ging, is available.
The XMEGA C4 devices have five software selectable power saving modes. The idle mode
stops the CPU while allowing the SRAM, 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 inter-
rupt, 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
standby mode, the external crystal oscillator keeps running while the rest of the device is sleep-
ing. 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. 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. 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 AVR XMEGA is a powerful microcontroller
family that provides a highly flexible and cost effective solution for many embedded applications.
All Atmel AVR XMEGA devices are supported with a full suite of program and system develop-
ment tools, including: C compilers, macro assemblers, program debugger/simulators,
programmers, and evaluation kits.