124
8161D–AVR–10/09
ATmega48PA/88PA/168PA/328P
15.8
Compare Match Output Unit
The Compare Output mode (COM1x1:0) bits have two functions. The Waveform Generator uses
the COM1x1:0 bits for defining the Output Compare (OC1x) state at the next compare match.
Secondly the COM1x1:0 bits control the OC1x pin output source. Figure 15-5 shows a simplified
schematic of the logic affected by the COM1x1:0 bit setting. The I/O Registers, I/O bits, and I/O
pins in the figure are shown in bold. Only the parts of the general I/O Port Control Registers
(DDR and PORT) that are affected by the COM1x1:0 bits are shown. When referring to the
OC1x state, the reference is for the internal OC1x Register, not the OC1x pin. If a system reset
occur, the OC1x Register is reset to “0”.
Figure 15-5. Compare Match Output Unit, Schematic
The general I/O port function is overridden by the Output Compare (OC1x) from the Waveform
Generator if either of the COM1x1:0 bits are set. However, the OC1x pin direction (input or out-
put) is still controlled by the Data Direction Register (DDR) for the port pin. The Data Direction
Register bit for the OC1x pin (DDR_OC1x) must be set as output before the OC1x value is visi-
ble on the pin. The port override function is generally independent of the Waveform Generation
mode, but there are some exceptions. Refer to Table 15-1, Table 15-2 and Table 15-3 for
details.
The design of the Output Compare pin logic allows initialization of the OC1x state before the out-
put is enabled. Note that some COM1x1:0 bit settings are reserved for certain modes of
The COM1x1:0 bits have no effect on the Input Capture unit.
15.8.1
Compare Output Mode and Waveform Generation
The Waveform Generator uses the COM1x1:0 bits differently in normal, CTC, and PWM modes.
For all modes, setting the COM1x1:0 = 0 tells the Waveform Generator that no action on the
OC1x Register is to be performed on the next compare match. For compare output actions in the
PORT
DDR
DQ
OCnx
Pin
OCnx
DQ
Waveform
Generator
COMnx1
COMnx0
0
1
D
ATA
B
U
S
FOCnx
clk
I/O
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