5
2552K–AVR–04/11
ATmega329/3290/649/6490
The Atmel
AVR core combines a rich instruction set with 32 general purpose working regis-
ters. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two
independent registers to be accessed in one single instruction executed in one clock cycle. The
resulting architecture is more code efficient while achieving throughputs up to ten times faster
than conventional CISC microcontrollers.
The Atmel ATmega329/3290/649/6490 provides the following features: 32/64K bytes of In-Sys-
tem Programmable Flash with Read-While-Write capabilities, 1/2K bytes EEPROM, 2/4K byte
SRAM, 54/69 general purpose I/O lines, 32 general purpose working registers, a JTAG interface
for Boundary-scan, On-chip Debugging support and programming, a complete On-chip LCD
controller with internal contrast control, three flexible Timer/Counters with compare modes, inter-
nal and external interrupts, a serial programmable USART, Universal Serial Interface with Start
Condition Detector, an 8-channel, 10-bit ADC, a programmable Watchdog Timer with internal
Oscillator, an SPI serial port, and five software selectable power saving modes. The Idle mode
stops the CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system to con-
tinue functioning. The Power-down mode saves the register contents but freezes the Oscillator,
disabling all other chip functions until the next interrupt or hardware reset. In Power-save mode,
the asynchronous timer and the LCD controller continues to run, allowing the user to maintain a
timer base and operate the LCD display while the rest of the device is sleeping. The ADC Noise
Reduction mode stops the CPU and all I/O modules except asynchronous timer, LCD controller
and ADC, to minimize switching noise during ADC conversions. In Standby mode, the crys-
tal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast
start-up combined with low-power consumption.
The device is manufactured using Atmel’s high density non-volatile memory technology. The
On-chip In-System re-Programmable (ISP) Flash allows the program memory to be repro-
grammed In-System through an SPI serial interface, by a conventional non-volatile memory
programmer, or by an On-chip Boot program running on the AVR core. The Boot program can
use any interface to download the application program in the Application Flash memory. Soft-
ware 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-bit RISC CPU with In-System
Self-Programmable Flash on a monolithic chip, the Atmel ATmega329/3290/649/6490 is a pow-
erful microcontroller that provides a highly flexible and cost effective solution to many embedded
control applications.
The Atmel ATmega329/3290/649/6490 is supported with a full suite of program and system
development tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators,
In-Circuit Emulators, and Evaluation kits.