6
2570NS–AVR–05/11
ATmega325/3250/645/6450
2.2
Comparison between ATmega325, ATmega3250, ATmega645 and ATmega6450
The ATmega325, ATmega3250, ATmega645, and ATmega6450 differ only in memory sizes, pin
count and pinout. Table 2-1 on page 6 summarizes the different configurations for the four
devices.
2.3
Pin Descriptions
The following section describes the I/O-pin special functions.
2.3.1
V
CC
Digital supply voltage.
2.3.2
GND
Ground.
2.3.3
Port A (PA7..PA0)
Port A is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The
Port A output buffers have symmetrical drive characteristics with both high sink and source
capability. As inputs, Port A pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port A pins are tri-stated when a reset condition becomes active,
even if the clock is not running.
2.3.4
Port B (PB7..PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The
Port B output buffers have symmetrical drive characteristics with both high sink and source
capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port B pins are tri-stated when a reset condition becomes active,
even if the clock is not running.
Port B has better driving capabilities than the other ports.
Po rt B al so se rve s t h e f u nct i o n s of va ri ou s spe c ial f e a t ur es of t h e At me l
ATmega325/3250/645/6450 as listed on page 68.
2.3.5
Port C (PC7..PC0)
Port C is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The
Port C output buffers have symmetrical drive characteristics with both high sink and source
capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port C pins are tri-stated when a reset condition becomes active,
even if the clock is not running.
Table 2-1.
Configuration Summary
Device
Flash
EEPROM
RAM
General Purpose
I/O Pins
ATmega325
32Kbytes
1Kbytes
2Kbytes
54
ATmega3250
32Kbytes
1Kbytes
2Kbytes
69
ATmega645
64Kbytes
2Kbytes
4Kbytes
54
ATmega6450
64Kbytes
2Kbytes
4Kbytes
69
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相关代理商/技术参数
ATMEGA3250V-8AJ 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit Microcontroller with In-System Programmable Flash
ATmega3250V-8AU 功能描述:8位微控制器 -MCU AVR 32K FLASH 1K EE 2K SRAM ADC 1.8V RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ATMEGA3250V-8AUR 功能描述:8位微控制器 -MCU AVR 32KB FLSH 1KB EE 2KB SRAM-8MHZ 1.8V RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ATmega325-16AI 功能描述:8位微控制器 -MCU AVR 32K FLASH 1K EE 2K SRAM ADC 5V 5V RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ATMEGA325-16AJ 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit Microcontroller with In-System Programmable Flash
ATmega325-16AU 功能描述:8位微控制器 -MCU 32kB Flash 1kB EEPROM 54 I/O Pins RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ATMEGA325-16AUR 功能描述:8位微控制器 -MCU AVR 32K FLSH 1K EE2K SRAM ADC 5V-16MHZ 5V RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ATmega325-16MI 功能描述:8位微控制器 -MCU AVR 32K FLASH 1K EE 2K SRAM ADC 5V 5V RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT