atmega3250v-8auatmega325v-8ai ATMEL Corporation, atmega3250v-8auatmega325v-8ai Datasheet - Page 5

• Manufacturer Part Number: atmega3250v-8auatmega325v-8ai
• Description: Atmega3250 8-bit Microcontroller With In-system Programmable Flash
• Manufacturer: ATMEL Corporation

3.2
3.3
2570L–AVR–08/07
Comparison between ATmega325, ATmega3250, ATmega645 and ATmega6450
Pin Descriptions
The ATmega325/3250/645/6450 provides the following features: 32/64K bytes of In-System
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, three flexible Timer/Counters
with compare modes, internal 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 continue 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 will continue to run, allowing the
user to maintain a timer base while the rest of the device is sleeping. The ADC Noise Reduction
mode stops the CPU and all I/O modules except asynchronous timer and ADC to minimize
switching noise during ADC conversions. In Standby mode, the crystal/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 ATmega325/3250/645/6450 is a pow-
erful microcontroller that provides a highly flexible and cost effective solution to many embedded
control applications.
The ATmega325/3250/645/6450 AVR 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.
The ATmega325, ATmega3250, ATmega645, and ATmega6450 differs only in memory sizes,
pin count and pinout.
devices.
Table 3-1.
The following section describes the I/O-pin special functions.
Device
ATmega325
ATmega3250
ATmega645
ATmega6450
Configuration Summary
Flash
32K bytes
32K bytes
64K bytes
64K bytes
Table 3-1 on page 5
EEPROM
1K bytes
1K bytes
2K bytes
2K bytes
summarizes the different configurations for the four
ATmega325/3250/645/6450
RAM
2K bytes
2K bytes
4K bytes
4K bytes
General Purpose
I/O Pins
54
69
54
69
5