收藏本站
参数资料
型号： ST72E734J6D0
厂商： STMICROELECTRONICS
元件分类： 微控制器/微处理器
英文描述： 8-BIT, UVPROM, 8 MHz, MICROCONTROLLER, CDIP42
封装： CERAMIC, SDIP-42
文件页数： 78/144页
文件大小： 1280K
代理商： ST72E734J6D0
ST72774/ST727754/ST72734
39/144
4.2 WATCHDOG TIMER (WDG)
4.2.1 Introduction
The Watchdog timer is used to detect the
occurrence of a software fault, usually generated
by external interference or by unforeseen logical
conditions, which causes the application program
to abandon its normal sequence. The Watchdog
circuit generates an MCU reset on expiry of a
programmed time period, unless the program
refreshes the counter’s contents before the T6 bit
becomes cleared.
4.2.2 Main Features
s
Programmable timer (64 increments of 49152
CPU cycles)
s
Programmable reset
s
Reset (if watchdog activated) when the T6 bit
reaches zero
Figure 26. Watchdog Block Diagram
4.2.3 Functional Description
The counter value stored in the CR register (bits
T6:T0), is decremented every 49,152 machine
cycles, and the length of the timeout period can be
programmed by the user in 64 increments.
If the watchdog is activated (the WDGA bit is set)
and when the 7-bit timer (bits T6:T0) rolls over
from 40h to 3Fh (T6 becomes cleared), it initiates a
reset cycle pulling low the reset pin for typically
500ns.
The application program must write in the CR
register
at
regular
intervals
during
normal
operation to prevent an MCU reset. The value to
be stored in the CR register must be between FFh
and C0h (see Table 13 . Watchdog Timing (fCPU =
8 MHz)):
– The WDGA bit is set (watchdog enabled)
– The T6 bit is set to prevent generating an imme-
diate reset
– The T5:T0 bits contain the number of increments
which represents the time delay before the
watchdog produces a reset.
RESET
WDGA
7-BIT DOWNCOUNTER
fCPU
T6
T0
CLOCK DIVIDER
WATCHDOG CONTROL REGISTER (CR)
÷49152
T1
T2
T3
T4
T5
相关PDF资料
PDF描述
ST72T774S9T1 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PQFP44
ST7294C6B6 8-BIT, MROM, 4 MHz, MICROCONTROLLER, PDIP28
ST72T94C6M6 8-BIT, OTPROM, MICROCONTROLLER, PDSO28
ST72C171K2B6 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDIP32
ST72E85A5G0 8-BIT, UVPROM, 4.332 MHz, MICROCONTROLLER, CQFP80
相关代理商/技术参数
参数描述
ST72F260G1B5 功能描述:8位微控制器 -MCU Flask 4K SPI 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
ST72F260G1M6 功能描述:8位微控制器 -MCU Flash 4K SPI/I2C/SCI 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
ST72F260G1M6/TR 功能描述:8位微控制器 -MCU 8B MCU FLASH OR ROM MEMORY 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
ST72F262G1B5 功能描述:8位微控制器 -MCU Flask 4K SPI 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
ST72F262G1B6 功能描述:8位微控制器 -MCU 8B MCU 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

*
*
*