5

8021DS–AVR–06/08

ATmega329P/3290P

The ATmega329P/3290P provides the following features: 32K bytes of In-System Programma-

ble Flash with Read-While-Write capabilities, 1K bytes EEPROM, 2K 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, internal and external inter-

rupts, 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 continue function-

ing. 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 asyn-

chronous 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 ATmega329P/3290P is a powerful

microcontroller that provides a highly flexible and cost effective solution to many embedded con-

trol applications.

The ATmega329P/3290P AVR is supported with a full suite of program and system develop-

ment tools including: C Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit

Emulators, and Evaluation kits.

2.2

Comparison between ATmega329P and ATmega3290P

The ATmega329P and ATmega3290P differs only in pin count and pinout. Table 2-1 on page 5

summarizes the different configurations for the four devices.

Table 2-1.

Configuration Summary

Device

Flash

EEPROM

RAM

LCD

Segments

General Purpose

I/O Pins

ATmega329P

32K bytes

1K bytes

2K bytes

4 x 25

54

ATmega3290P

32K bytes

1K bytes

2K bytes

4 x 40

69