- 您现在的位置：买卖IC网 > Sheet目录1905 > ATMEGA48PA-MMNR (Atmel)MCU AVR 4KB FLASH 20MHZ 28QFN
164
8161D–AVR–10/09
ATmega48PA/88PA/168PA/328P
17.11.8
ASSR – Asynchronous Status Register
Bit 7 – RES: Reserved bit
This bit is reserved and will always read as zero.
Bit 6 – EXCLK: Enable External Clock Input
When EXCLK is written to one, and asynchronous clock is selected, the external clock input buf-
fer is enabled and an external clock can be input on Timer Oscillator 1 (TOSC1) pin instead of a
32 kHz crystal. Writing to EXCLK should be done before asynchronous operation is selected.
Note that the crystal Oscillator will only run when this bit is zero.
Bit 5 – AS2: Asynchronous Timer/Counter2
When AS2 is written to zero, Timer/Counter2 is clocked from the I/O clock, clk
I/O. When AS2 is
written to one, Timer/Counter2 is clocked from a crystal Oscillator connected to the Timer Oscil-
lator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of TCNT2, OCR2A,
OCR2B, TCCR2A and TCCR2B might be corrupted.
Bit 4 – TCN2UB: Timer/Counter2 Update Busy
When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes set.
When TCNT2 has been updated from the temporary storage register, this bit is cleared by hard-
ware. A logical zero in this bit indicates that TCNT2 is ready to be updated with a new value.
Bit 3 – OCR2AUB: Output Compare Register2 Update Busy
When Timer/Counter2 operates asynchronously and OCR2A is written, this bit becomes set.
When OCR2A has been updated from the temporary storage register, this bit is cleared by hard-
ware. A logical zero in this bit indicates that OCR2A is ready to be updated with a new value.
Bit 2 – OCR2BUB: Output Compare Register2 Update Busy
When Timer/Counter2 operates asynchronously and OCR2B is written, this bit becomes set.
When OCR2B has been updated from the temporary storage register, this bit is cleared by hard-
ware. A logical zero in this bit indicates that OCR2B is ready to be updated with a new value.
Bit 1 – TCR2AUB: Timer/Counter Control Register2 Update Busy
When Timer/Counter2 operates asynchronously and TCCR2A is written, this bit becomes set.
When TCCR2A has been updated from the temporary storage register, this bit is cleared by
hardware. A logical zero in this bit indicates that TCCR2A is ready to be updated with a new
value.
Bit 0 – TCR2BUB: Timer/Counter Control Register2 Update Busy
When Timer/Counter2 operates asynchronously and TCCR2B is written, this bit becomes set.
When TCCR2B has been updated from the temporary storage register, this bit is cleared by
hardware. A logical zero in this bit indicates that TCCR2B is ready to be updated with a new
value.
If a write is performed to any of the five Timer/Counter2 Registers while its update busy flag is
set, the updated value might get corrupted and cause an unintentional interrupt to occur.
Bit
7
6
5
4
3
2
1
0
–
EXCLK
AS2
TCN2UB
OCR2AUB
OCR2BUB
TCR2AUB
TCR2BUB
ASSR
Read/Write
R
R/W
R
Initial Value
0
发布紧急采购，3分钟左右您将得到回复。
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