参数资料
型号: TS87C51RB2-EBR
厂商: ATMEL CORP
元件分类: 微控制器/微处理器
英文描述: 8-BIT, OTPROM, MICROCONTROLLER, PQCC44
封装: PLASTIC, LCC-44
文件页数: 41/74页
文件大小: 689K
代理商: TS87C51RB2-EBR
46
Rev. C - 06 March, 2001
TS80C51RA2/RD2
TS83C51RB2/RC2/RD2
TS87C51RB2/RC2/RD2
6.10. Hardware Watchdog Timer
The WDT is intended as a recovery method in situations where the CPU may be subjected to software upset. The
WDT consists of a 14-bit counter and the WatchDog Timer ReSeT (WDTRST) SFR. The WDT is by default
disabled from exiting reset. To enable the WDT, user must write 01EH and 0E1H in sequence to the WDTRST,
SFR location 0A6H. When WDT is enabled, it will increment every machine cycle while the oscillator is running
and there is no way to disable the WDT except through reset (either hardware reset or WDT overflow reset). When
WDT overflows, it will drive an output RESET HIGH pulse at the RST-pin.
6.10.1. Using the WDT
To enable the WDT, user must write 01EH and 0E1H in sequence to the WDTRST, SFR location 0A6H. When
WDT is enabled, the user needs to service it by writing to 01EH and 0E1H to WDTRST to avoid WDT overflow.
The 14-bit counter overflows when it reaches 16383 (3FFFH) and this will reset the device. When WDT is enabled,
it will increment every machine cycle while the oscillator is running. This means the user must reset the WDT at
least every 16383 machine cycle. To reset the WDT the user must write 01EH and 0E1H to WDTRST. WDTRST
is a write only register. The WDT counter cannot be read or written. When WDT overflows, it will generate an
output RESET pulse at the RST-pin. The RESET pulse duration is 96 x TOSC , where TOSC = 1/FOSC . To make
the best use of the WDT, it should be serviced in those sections of code that will periodically be executed within
the time required to prevent a WDT reset.
To have a more powerful WDT, a 27 counter has been added to extend the Time-out capability, ranking from
16ms to 2s @ FOSC = 12MHz. To manage this feature, refer to WDTPRG register description, Table 24. (SFR0A7h).
Table 23. WDTRST Register
WDTRST Address (0A6h)
Write only, this SFR is used to reset/enable the WDT by writing 01EH then 0E1H in sequence.
7
6
5
4
3
2
1
Reset value
X
相关PDF资料
PDF描述
TS80C51RD2-MCBB 8-BIT, 40 MHz, MICROCONTROLLER, PQCC44
TS83C51RB2ZZZ-VCBB 8-BIT, MROM, 40 MHz, MICROCONTROLLER, PQCC44
TS80C51RD2-MCLB 8-BIT, 40 MHz, MICROCONTROLLER, PQCC68
TS83C51RB2ZZZ-LCEB 8-BIT, MROM, 30 MHz, MICROCONTROLLER, PQFP44
TS87C51RD2-MIMB 8-BIT, OTPROM, 40 MHz, MICROCONTROLLER, PQFP64
相关代理商/技术参数
参数描述
TS87C51RB2-EEB 制造商:未知厂家 制造商全称:未知厂家 功能描述:Microcontroller
TS87C51RB2-EED 制造商:未知厂家 制造商全称:未知厂家 功能描述:Microcontroller
TS87C51RB2-EER 制造商:未知厂家 制造商全称:未知厂家 功能描述:Microcontroller
TS87C51RB2-LCA 功能描述:IC MCU 8BIT 16K OTP 30MHZ 40-DIP RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器, 系列:87C 标准包装:9 系列:87C 核心处理器:8051 芯体尺寸:8-位 速度:40/20MHz 连通性:UART/USART 外围设备:POR,WDT 输入/输出数:32 程序存储器容量:32KB(32K x 8) 程序存储器类型:OTP EEPROM 大小:- RAM 容量:256 x 8 电压 - 电源 (Vcc/Vdd):4.5 V ~ 5.5 V 数据转换器:- 振荡器型:内部 工作温度:0°C ~ 70°C 封装/外壳:40-DIP(0.600",15.24mm) 包装:管件
TS87C51RB2-LCAD 制造商:未知厂家 制造商全称:未知厂家 功能描述:8-Bit Microcontroller