ATmega128
I/O Ports
Introduction
All Atmel ? AVR ? ports have true Read-Modify- W rite functionality when used as general digital
I/O ports. This means that the direction of one port pin can be changed without unintentionally
changing the direction of any other pin with the SBI and CBI instructions. The same applies
when changing drive value (if configured as output) or enabling/disabling of pull-up resistors (if
configured as input). Each output buffer has symmetrical drive characteristics with both high sink
and source capability. The pin driver is strong enough to drive LED displays directly. All port pins
have individually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O
pins have protection diodes to both V CC and Ground as indicated in Figure 29 . Refer to “Electri-
cal Characteristics” on page 318 for a complete list of parameters.
Figure 29. I/O Pin Equivalent Schematic
R PU
Pxn
C PIN
Logic
See Figure
"General Digital I/O" for
Details
All registers and bit references in this section are written in general form. A lower case “x” repre-
sents the numbering letter for the port, and a lower case “n” represents the bit number. However,
when using the register or bit defines in a program, the precise form must be used. For example,
PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O regis-
ters and bit locations are listed in “Register Description for I/O Ports” on page 86 .
Three I/O memory address locations are allocated for each port, one each for the Data Register
– PORTx, Data Direction Register – DDRx, and the Port Input Pins – PINx. The Port Input Pins
I/O location is read only, while the Data Register and the Data Direction Register are read/write.
In addition, the Pull-up Disable – PUD bit in SFIOR disables the pull-up function for all pins in all
ports when set.
Using the I/O port as General Digital I/O is described in “Ports as General Digital I/O” on page
66 . Most port pins are multiplexed with alternate functions for the peripheral features on the
device. How each alternate function interferes with the port pin is described in “Alternate Port
Functions” on page 70 . Refer to the individual module sections for a full description of the alter-
nate functions.
Note that enabling the alternate function of some of the port pins does not affect the use of the
other pins in the port as General Digital I/O.
65
2467X–AVR–06/11
相关PDF资料
ATMEGA64RZAPV-10AU BUNDLE ATMEGA644P/AT86RF230 TQFP
ATP101-TL-H MOSFET P-CH 30V 25A ATPAK
ATP102-TL-H MOSFET P-CH 30V 40A ATPAK
ATP103-TL-H MOSFET P-CH 30V 55A ATPAK
ATP104-TL-H MOSFET P-CH 30V 75A ATPAK
ATP106-TL-H MOSFET P-CH 40V 30A ATPAK
ATP107-TL-H MOSFET P-CH 40V 50A ATPAK
ATP108-TL-H MOSFET P-CH 40V 70A ATPAK
相关代理商/技术参数
ATMEGA128RFA1-ZUR SL514 制造商:Atmel Corporation 功能描述:
ATMEGA128RFA1-ZUR00 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC REVF 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC REVF T&R - Bulk 制造商:Atmel from Components Direct 功能描述:ATMEL ATMEGA128RFA1-ZUR00 MICROCONTROLLERS (MCU) 制造商:Atmel 功能描述:Atmel ATMEGA128RFA1-ZUR00 Microcontrollers (MCU) 制造商:Atmel Corporation 功能描述:MCU AVR 2.4GHZ 128K FLASH 64VQFN 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC Revision F 制造商:Atmel 功能描述:2.4GHZ 802.15.4 128K SOC REVF
ATMEGA128RFR2-ZF 功能描述:IC RF TXRX+MCU 802.15.4 64-VFQFN 制造商:microchip technology 系列:- 包装:托盘 零件状态:在售 类型:TxRx + MCU 射频系列/标准:802.15.4 协议:Zigbee? 调制:DSSS, O-QPSK 频率:2.4GHz 数据速率(最大值):2Mbps 功率 - 输出:3.5dBm 灵敏度:-100dBm 存储容量:128kB 闪存,4kB EEPROM,16kB SRAM 串行接口:I2C,JTAG,SPI,USART GPIO:35 电压 - 电源:1.8 V ~ 3.6 V 电流 - 接收:5mA ~ 12.5mA 电流 - 传输:8mA ~ 14.5mA 工作温度:-40°C ~ 125°C 封装/外壳:64-VFQFN 裸露焊盘 标准包装:260
ATMEGA128RFR2-ZU 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC IND 85C - Bulk
ATMEGA128RFR2-ZUR 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC 85C T&R - Tape and Reel
ATMEGA128RZAV-8AU 功能描述:射频微控制器 - MCU AVR Z-Link Bundle RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:Si100x 数据总线宽度:8 bit 最大时钟频率:24 MHz 程序存储器大小:64 KB 数据 RAM 大小:4 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 + 85 C 封装 / 箱体:LGA-42 安装风格:SMD/SMT 封装:Tube
ATMEGA128RZAV-8MU 功能描述:射频微控制器 - MCU AVR Z-Link Bundle RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:Si100x 数据总线宽度:8 bit 最大时钟频率:24 MHz 程序存储器大小:64 KB 数据 RAM 大小:4 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 + 85 C 封装 / 箱体:LGA-42 安装风格:SMD/SMT 封装:Tube