收藏本站
参数资料
型号： ATMEGA644A-MU
厂商： Atmel
文件页数： 55/160页
文件大小： 0K
描述： IC MCU AVR 64K FLASH 44VQFN
产品培训模块： MCU Product Line Introduction
megaAVR Introduction
标准包装： 416
系列： AVR® ATmega
核心处理器： AVR
芯体尺寸： 8-位
速度： 20MHz
连通性： I²C，SPI，UART/USART
外围设备： 欠压检测/复位，POR，PWM，WDT
输入/输出数： 32
程序存储器容量： 64KB（32K x 16）
程序存储器类型： 闪存
EEPROM 大小： 2K x 8
RAM 容量： 4K x 8
电压 - 电源 (Vcc/Vdd)： 1.8 V ~ 5.5 V
数据转换器： A/D 8x10b
振荡器型： 内部
工作温度： -40°C ~ 85°C
封装/外壳： 44-VFQFN 裸露焊盘
包装： 托盘
148
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
Register bit for the OC2x pin (DDR_OC2x) must be set as output before the OC2x value is visi-
ble on the pin. The port override function is independent of the Waveform Generation mode.
The design of the Output Compare pin logic allows initialization of the OC2x state before the out-
put is enabled. Note that some COM2x1:0 bit settings are reserved for certain modes of
operation. See ”Register description” on page 157.
17.6.1
Compare Output Mode and Waveform Generation
The Waveform Generator uses the COM2x1:0 bits differently in normal, CTC, and PWM modes.
For all modes, setting the COM2x1:0 = 0 tells the Waveform Generator that no action on the
OC2x Register is to be performed on the next compare match. For compare output actions in the
non-PWM modes refer to Table 17-5 on page 158. For fast PWM mode, refer to Table 17-6 on
page 158, and for phase correct PWM refer to Table 17-7 on page 159.
A change of the COM2x1:0 bits state will have effect at the first compare match after the bits are
written. For non-PWM modes, the action can be forced to have immediate effect by using the
FOC2x strobe bits.
17.7
Modes of operation
The mode of operation, that is, the behavior of the Timer/Counter and the Output Compare pins,
is defined by the combination of the Waveform Generation mode (WGM22:0) and Compare Out-
put mode (COM2x1:0) bits. The Compare Output mode bits do not affect the counting sequence,
while the Waveform Generation mode bits do. The COM2x1:0 bits control whether the PWM out-
put generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes
the COM2x1:0 bits control whether the output should be set, cleared, or toggled at a compare
match (See “Compare Match Output unit” on page 147).
For detailed timing information refer to ”Timer/Counter Timing diagrams” on page 152.
17.7.1
Normal Mode
The simplest mode of operation is the Normal mode (WGM22:0 = 0). In this mode the counting
direction is always up (incrementing), and no counter clear is performed. The counter simply
overruns when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bot-
tom (0x00). In normal operation the Timer/Counter Overflow Flag (TOV2) will be set in the same
timer clock cycle as the TCNT2 becomes zero. The TOV2 Flag in this case behaves like a ninth
bit, except that it is only set, not cleared. However, combined with the timer overflow interrupt
that automatically clears the TOV2 Flag, the timer resolution can be increased by software.
There are no special cases to consider in the Normal mode, a new counter value can be written
anytime.
The Output Compare unit can be used to generate interrupts at some given time. Using the Out-
put Compare to generate waveforms in Normal mode is not recommended, since this will
occupy too much of the CPU time.
17.7.2
Clear Timer on Compare Match (CTC) Mode
In Clear Timer on Compare or CTC mode (WGM22:0 = 2), the OCR2A Register is used to
manipulate the counter resolution. In CTC mode the counter is cleared to zero when the counter
value (TCNT2) matches the OCR2A. The OCR2A defines the top value for the counter, hence
also its resolution. This mode allows greater control of the compare match output frequency. It
also simplifies the operation of counting external events.
相关PDF资料
PDF描述
1-5221629-6 CONN TERMINATOR BNC 50 OHM GOLD
ATSAM3N4BA-AU MCU FLASH 64-QFP
1-221629-6 CONN TERMINATOR BNC 50 OHM GOLD
221629-5 CONN TERMINATR PLUG BNC 75OHM AU
5221629-5 CONN TERMINATR PLUG BNC 75OHM AU
相关代理商/技术参数
参数描述
ATMEGA644A-MUR 功能描述:8位微控制器 -MCU 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
ATMEGA644A-PU 功能描述:8位微控制器 -MCU 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
ATMEGA644P-15AT 功能描述:8位微控制器 -MCU AVR 64K FLSH 4K SRAM 2KB EE 20MHZ 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
ATMEGA644P-15AT1 功能描述:8位微控制器 -MCU AVR 64K FLSH 4K SRAM 2KB EE 20MHZ 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
ATMEGA644P-15AZ 功能描述:8位微控制器 -MCU AVR 64K FLSH 4K SRAM 2KB EE 20MHZ 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
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

*
*
*