参数资料
型号: ATMEGA644P-B15MZ
厂商: Atmel
文件页数: 52/70页
文件大小: 0K
描述: IC MCU 8BIT 64KB FLASH 32VQFN
标准包装: 4,000
系列: AVR® ATmega
核心处理器: AVR
芯体尺寸: 8-位
速度: 16MHz
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): 2.7 V ~ 5.5 V
数据转换器: A/D 8x10b
振荡器型: 内部
工作温度: -40°C ~ 125°C
封装/外壳: 44-VFQFN 裸露焊盘
包装: 带卷 (TR)
40
7674F–AVR–09/09
ATmega164P/324P/644P
7.12.2
CLKPR – Clock Prescale Register
Bit 7 – CLKPCE: Clock Prescaler Change Enable
The CLKPCE bit must be written to logic one to enable change of the CLKPS bits. The CLKPCE
bit is only updated when the other bits in CLKPR are simultaneously written to zero. CLKPCE is
cleared by hardware four cycles after it is written or when CLKPS bits are written. Rewriting the
CLKPCE bit within this time-out period does neither extend the time-out period, nor clear the
CLKPCE bit.
Bits 3:0 – CLKPS3:0: Clock Prescaler Select Bits 3 - 0
These bits define the division factor between the selected clock source and the internal system
clock. These bits can be written run-time to vary the clock frequency to suit the application
requirements. As the divider divides the master clock input to the MCU, the speed of all synchro-
nous peripherals is reduced when a division factor is used. The division factors are given in
The CKDIV8 Fuse determines the initial value of the CLKPS bits. If CKDIV8 is unprogrammed,
the CLKPS bits will be reset to “0000”. If CKDIV8 is programmed, CLKPS bits are reset to
“0011”, giving a division factor of 8 at start up. This feature should be used if the selected clock
source has a higher frequency than the maximum frequency of the device at the present operat-
ing conditions. Note that any value can be written to the CLKPS bits regardless of the CKDIV8
Fuse setting. The Application software must ensure that a sufficient division factor is chosen if
the selected clock source has a higher frequency than the maximum frequency of the device at
the present operating conditions. The device is shipped with the CKDIV8 Fuse programmed.
Bit
7
6
5
4
32
10
CLKPCE
CLKPS3
CLKPS2
CLKPS1
CLKPS0
CLKPR
Read/Write
R/W
R
R/W
Initial Value
0
See Bit Description
Table 7-16.
Clock Prescaler Select
CLKPS3
CLKPS2
CLKPS1
CLKPS0
Clock Division Factor
00
1
00
01
2
00
10
4
00
11
8
01
00
16
01
32
01
10
64
01
11
128
10
00
256
10
01
Reserved
10
Reserved
10
11
Reserved
11
00
Reserved
11
01
Reserved
11
10
Reserved
11
Reserved
相关PDF资料
PDF描述
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
相关代理商/技术参数
参数描述
ATMEGA644PR212-AU 功能描述:8位微控制器 -MCU ATmega 644PV-10AU AT86RF212-ZU 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
ATMEGA644PR212-MU 功能描述:8位微控制器 -MCU ATmega 644PV-10MU AT86RF212-ZU 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
ATMEGA644PR231-AU 功能描述:8位微控制器 -MCU ATmega 644PV-10AU AT86RF231-ZU 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
ATMEGA644PR231-MU 功能描述:8位微控制器 -MCU ATmega 644PV-10MU AT86RF231-ZU 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
ATMEGA644PV-10AQ 功能描述:8位微控制器 -MCU AVR 64KB, 2KB EE 20MHz 4KB SRAM, 1.8V 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