收藏本站
121
8161D–AVR–10/09
ATmega48PA/88PA/168PA/328P
tion mode (WGM13:0) bits must be set before the TOP value can be written to the ICR1
Register. When writing the ICR1 Register the high byte must be written to the ICR1H I/O location
before the low byte is written to ICR1L.
For more information on how to access the 16-bit registers refer to ”Accessing 16-bit Registers”
on page 115.
15.6.1
Input Capture Trigger Source
The main trigger source for the Input Capture unit is the Input Capture pin (ICP1).
Timer/Counter1 can alternatively use the Analog Comparator output as trigger source for the
Input Capture unit. The Analog Comparator is selected as trigger source by setting the Analog
Comparator Input Capture (ACIC) bit in the Analog Comparator Control and Status Register
(ACSR). Be aware that changing trigger source can trigger a capture. The Input Capture Flag
must therefore be cleared after the change.
Both the Input Capture pin (ICP1) and the Analog Comparator output (ACO) inputs are sampled
using the same technique as for the T1 pin (Figure 16-1 on page 141). The edge detector is also
identical. However, when the noise canceler is enabled, additional logic is inserted before the
edge detector, which increases the delay by four system clock cycles. Note that the input of the
noise canceler and edge detector is always enabled unless the Timer/Counter is set in a Wave-
form Generation mode that uses ICR1 to define TOP.
An Input Capture can be triggered by software by controlling the port of the ICP1 pin.
15.6.2
Noise Canceler
The noise canceler improves noise immunity by using a simple digital filtering scheme. The
noise canceler input is monitored over four samples, and all four must be equal for changing the
output that in turn is used by the edge detector.
The noise canceler is enabled by setting the Input Capture Noise Canceler (ICNC1) bit in
Timer/Counter Control Register B (TCCR1B). When enabled the noise canceler introduces addi-
tional four system clock cycles of delay from a change applied to the input, to the update of the
ICR1 Register. The noise canceler uses the system clock and is therefore not affected by the
prescaler.
15.6.3
Using the Input Capture Unit
The main challenge when using the Input Capture unit is to assign enough processor capacity
for handling the incoming events. The time between two events is critical. If the processor has
not read the captured value in the ICR1 Register before the next event occurs, the ICR1 will be
overwritten with a new value. In this case the result of the capture will be incorrect.
When using the Input Capture interrupt, the ICR1 Register should be read as early in the inter-
rupt handler routine as possible. Even though the Input Capture interrupt has relatively high
priority, the maximum interrupt response time is dependent on the maximum number of clock
cycles it takes to handle any of the other interrupt requests.
Using the Input Capture unit in any mode of operation when the TOP value (resolution) is
actively changed during operation, is not recommended.
Measurement of an external signal’s duty cycle requires that the trigger edge is changed after
each capture. Changing the edge sensing must be done as early as possible after the ICR1
Register has been read. After a change of the edge, the Input Capture Flag (ICF1) must be
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
ATMEGA644P-B15MZ IC MCU 8BIT 64KB FLASH 32VQFN
ATMEGA644V-10PU IC AVR MCU FLASH 64K 40DIP
ATMEGA645V-8MI IC AVR MCU FLASH 64K 1.8V 64QFN
ATMEGA649-16MI IC AVR MCU FLASH 64K 5V 64QFN
ATMEGA649V-8MI IC AVR MCU FLASH 64K 1.8V 64QFN
ATMEGA8515L-8JUR MCU AVR 8KB FLASH 8MHZ 44PLCC
ATMEGA8515L-8PJ IC MCU AVR 8K 5V 8MHZ 40-DIP
ATMEGA8535-16JUR MCU AVR 8K FLASH 16MHZ 44PLCC
相关代理商/技术参数
ATMEGA48PA-MN 功能描述:8位微控制器 -MCU AVR 4KB FL 256B EE 512B SRAM 20MHz 105C 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
ATMEGA48PA-MNR 功能描述:8位微控制器 -MCU AVR 4KB FL 256B EE 512B SRAM 20MHz 105C 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
ATMEGA48PA-MU 功能描述:8位微控制器 -MCU AVR 4KB FLASH 20 MHZ,IND TEMP 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
ATMEGA48PA-MU@SL383 制造商:Atmel 功能描述:MCU 8-bit ATmega AVR RISC 4KB Flash 2.5V/3.3V/5V 32-Pin QFN EP T/R
ATMEGA48PA-MUR 功能描述:8位微控制器 -MCU AVR 4KB FLSH 256B EE 512B SRAM-20MHz IND 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
ATMEGA48PA-PN 功能描述:8位微控制器 -MCU AVR 4KB FL 256B EE 512B SRAM 20MHz 105C 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
ATMEGA48PA-PU 功能描述:8位微控制器 -MCU AVR 4KB FLASH 20 MHZ,IND TEMP 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
ATMEGA48PB-AN 功能描述:AVR AVR? ATmega Microcontroller IC 8-Bit 20MHz 4KB (2K x 16) FLASH 32-TQFP 制造商:atmel 系列:AVR? ATmega 包装:托盘 零件状态:有效 核心处理器:AVR 核心尺寸:8-位 速度:20MHz 连接性:I2C，SPI，UART/USART 外设:欠压检测/复位，POR，PWM，WDT I/O 数:27 程序存储容量:4KB（2K x 16） 程序存储器类型:闪存 EEPROM 容量:256 x 8 RAM 容量:512 x 8 电压 - 电源（Vcc/Vdd）:1.8 V ~ 5.5 V 数据转换器:A/D 8x10b 振荡器类型:内部 工作温度:-40°C ~ 105°C（TA） 封装/外壳:32-TQFP 供应商器件封装:32-TQFP 标准包装:250