77
9140CINDCO02/10
ATA8741
19.2.6
Unconnected Pins
If some pins are unused, it is recommended to ensure that these pins have a defined level. Even
though most of the digital inputs are disabled in the deep sleep modes as described above, float-
ing inputs should be avoided to reduce current consumption in all other modes where the digital
inputs are enabled (Reset, Active mode and Idle mode).
The simplest method to ensure a defined level of an unused pin, is to enable the internal pull-up.
In this case, the pull-up will be disabled during reset. If low power consumption during reset is
important, it is recommended to use an external pull-up or pulldown. Connecting unused pins
directly to V
CC
 or GND is not recommended, since this may cause excessive currents if the pin is
accidentally configured as an output.
19.3   Alternate Port Functions
Most port pins have alternate functions in addition to being general digital I/Os. Figure 19-5 on
page 78 shows how the port pin control signals from the simplified Figure 19-2 on page 73 can
be overridden by alternate functions. The overriding signals may not be present in all port pins,
but the figure serves as a generic description applicable to all port pins in the AVR microcon-
troller family.
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相关代理商/技术参数
ATA8742 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Microcontroller with UHF ASK/FSK Transmitter
ATA8742C- PXQW 制造商:Atmel Corporation 功能描述:Embedded C incl RF Tx for 433 MHz
ATA8742C-PXQW 功能描述:8位微控制器 -MCU 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
ATA8742C-PXQW-1 功能描述:EMBEDDED INCL RF TX FOR 433 MHZ 制造商:microchip technology 系列:- 包装:剪切带(CT) 零件状态:在售 频率:429MHz ~ 439MHz 应用:通用 调制或协议:UHF 数据速率(最大值):32kbps 功率 - 输出:7.5dBm 电流 - 传输:9.8mA 数据接口:SPI 天线连接器:PCB,表面贴装 存储容量:4kB 闪存,256B EEPROM,256B SRAM 特性:- 电压 - 电源:2 V ~ 4 V 工作温度:-40°C ~ 85°C 封装/外壳:24-VQFN 裸露焊盘 标准包装:1
ATA8742-PXQW 功能描述:8位微控制器 -MCU Embedded uC incl RF Tx for 433 MHz 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
ATA8743 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Microcontroller with UHF ASK/FSK Transmitter
ATA8743C- PXQW 功能描述:8位微控制器 -MCU Embedded uC incl RF Tx for 315 MHz 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
ATA8743C-PXQW 制造商:Atmel Corporation 功能描述:EMBEDDED ?C INCL RF TX FOR 868 MHZ - Trays 制造商:Atmel Corporation 功能描述:EMBEDDED C INCL 868MHZ TX