參數(shù)資料
型號: AT87C51RC2
廠商: International Rectifier
英文描述: High Performance 8-bit Microcontroller
中文描述: 高性能8位微控制器
文件頁數(shù): 33/85頁
文件大?。?/td> 762K
代理商: AT87C51RC2
33
4188E–8051–08/06
AT/TS8xC51Rx2
Figure 6-9.
PCA PWM Mode
6.3.5
PCA Watchdog Timer
An on-board watchdog timer is available with the PCA to improve the reliability of the system
without increasing chip count. Watchdog timers are useful for systems that are susceptible to
noise, power glitches, or electrostatic discharge. Module 4 is the only PCA module that can be
programmed as a watchdog. However, this module can still be used for other modes if the
watchdog is not needed. Figure 6-7 shows a diagram of how the watchdog works. The user pre-
loads a 16-bit value in the compare registers. Just like the other compare modes, this 16-bit
value is compared to the PCA timer value. If a match is allowed to occur, an internal reset will be
generated. This will not cause the RST pin to be driven high.
In order to hold off the reset, the user has three options:
1. Periodically change the compare value so it will never match the PCA timer,
2. periodically change the PCA timer value so it will never match the compare values, or
3. Disable the watchdog by clearing the WDTE bit before a match occurs and then re-enable
it.
The first two options are more reliable because the watchdog timer is never disabled as in option
#3. If the program counter ever goes astray, a match will eventually occur and cause an internal
reset. The second option is also not recommended if other PCA modules are being used.
Remember, the PCA timer is the time base for all modules; changing the time base for other
modules would not be a good idea. Thus, in most applications the first solution is the best option.
This watchdog timer won’t generate a reset out on the reset pin.
CL
CCAPnH
CCAPnL
ECOMn
CCAPMn, n= 0 to 4
0xDA to 0xDE
CAPNn MATn TOGn PWMn ECCFn
CAPPn
8 bit comparator
CEXn
“0”
“1”
<
Enable
PCA counter/timer
Overflow
相關(guān)PDF資料
PDF描述
AT87C51RC2-3CSUL High Performance 8-bit Microcontroller
AT87C51RC2-3CSUM High Performance 8-bit Microcontroller
AT87C51RC2-RLTUL High Performance 8-bit Microcontroller
AT87C51RC2-RLTUM High Performance 8-bit Microcontroller
AT87C51RC2-SLSUL High Performance 8-bit Microcontroller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AT87C51RC2-3CSUL 功能描述:8位微控制器 -MCU OTP RC/32K 40MHZ 3V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT87C51RC2-3CSUM 功能描述:8位微控制器 -MCU 32KB SCMOS 3/2 .5 OTP RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT87C51RC2-RLTUL 功能描述:8位微控制器 -MCU OTP RC/32K 40MHZ 3V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT87C51RC2-RLTUM 功能描述:8位微控制器 -MCU 71RCX2 LYNX 32K OTP PCA DBLE D RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT87C51RC2-SLSUL 功能描述:8位微控制器 -MCU OTP RC/32K 40MHZ 3V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT