The UCCx946 is designed to provide accurate microprocessor supervision, including reset and watchdog functions. During power up, the device asserts a reset signal RES with VDD as low as 1 V. The reset signal remains asserted until the VDD voltage rises and remains above the reset threshold for the reset period. Both reset threshold and reset period are programmable by the user.
The UCCx946 is also resistant to glitches on the VDD line. Once RES has been deasserted, any drops below the threshold voltage need to be of certain time duration and voltage magnitude to generate a reset signal. These values are shown in Figure 1. An I/O line of the microprocessor may be tied to the watchdog input (WDI) for watchdog functions. If the I/O line is not toggled within a set watchdog period, programmable by the user, WDO is asserted. The watchdog function is disabled during reset condition Le lun. 16 mai 2016 09:50, Micka <[email protected]> a écrit : > You dont need an external microcontroller.... Some watchdog from Texas do > a good job like the uccx946. > > Le lun. 16 mai 2016 09:01, arsi <[email protected]> a écrit : > >> Hi, >> >> I use this: >> >> >> >> >> >> PIC 10F200 source code: >> >> /* >> File: main.c >> Author: arsi >> >> Created on May 22, 2015, 10:32 AM >> */#include <xc.h>#include <stdbool.h>#include <stdint.h>#define _XTAL_FREQ >> 4000000#pragma config WDTE = ON // Watchdog Timer (WDT >> enabled)#pragma config CP = OFF // Code Protect (Code protection >> off)#pragma config MCLRE = OFF // Master Clear Enable (GP3/MCLR pin >> fuction is digital I/O, MCLR internally tied to VDD) >> void delay1() { >> __delay_ms(1000); >> }bool flag = false;int counter = 0; >> void main(void) {#asm >> CLRWDT >> CLRF TMR0 >> CLRWDT >> MOVLW 0b00001111 >> OPTION#endasm >> CLRWDT(); >> TRIS = 0b1110; >> CLRWDT(); >> GP0 = 0; >> __delay_ms(500); >> CLRWDT(); >> TRIS = 0b1111; >> CLRWDT(); >> //pause for BBB boot up >> for (int i = 0; i < 120; i++) { >> delay1(); >> CLRWDT(); >> } >> counter = 0; >> while (true) { >> delay1(); >> if (counter < 120) { >> CLRWDT(); >> } >> if (flag != GP1) { >> counter = 0; >> flag = GP1; >> } else { >> counter++; >> } >> >> } >> } >> >> >> >> ******************************************************************************************* >> wd script on BBB: >> >> #!/bin/bash >> sleep 10 >> echo 60 > /sys/class/gpio/export >> echo "out" > /sys/class/gpio/gpio60/directionwhile :do >> echo "0" > /sys/class/gpio/gpio60/value >> sleep 1 >> echo "1" > /sys/class/gpio/gpio60/value >> sleep 1 >> >> done >> >> >> >> *********************************************************************************************** >> >> Arsi >> >> ------------------------------ >> >> *From:* Kb2pnm >> *Sent:* Saturday, March 22, 2014 6:08PM >> *To:* Beagleboard >> *Subject:* [beagleboard] Hardware watchdog for BBB >> >> >> HI, I have been working for a wile on safe power supply for BBB with >> backup power provided by supercapacitors. In case of power failure there >> is just enough time to safely and nicely shut down BBB. For some reason >> BBB does not always wake up fully. I need hardware dogwatch. Did anybody >> design such a thing? I was able to find some design for ardunio: >> http://www.playwitharduino.com/?p=291. >> Anybody has any experience with hardware dogwatch for BBB?? >> Thanks in advance >> Robert >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> >> >> >> >> >> >> >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/57397009.2000005%40chello.sk >> <https://groups.google.com/d/msgid/beagleboard/57397009.2000005%40chello.sk?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAF%2BMRtkm9n5fjiJsnABYL%2BJ%3DGiJO91RM_uKAwE8Lxa4b-osnBg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
