How to output a watchdog signal

[ashifulk]

Hello, I'm trying to interface an Infineon TLE4263-2ES voltage regulator with a external watchdog figure. The microcontroller is from the Freescale S12G family. My question is kind of gereic, in a way. When I'm sending a pulse signal to the voltage regulator from the micro, at what frequency should I send the signal in? I will be using a timer based interrupt to do this.

Attached are the watchdog and reset information from the voltage regulator datasheet. Any help is appreciated.

 

[meBigGuy]

If you look at figure 5 at the very end of the data sheet, it shows that you need a positive edge on the watchdog input to reset the timer. The rate of positive edges has to be faster than the timeout time, obviously. The equations under the picture explain how to determine the timeout time.

With Cd = 100nF the shortest timeout time (given part to part variation) is 16ms. Change Cd to 200nf for 32ms, etc (per the formula)

 

[ashifulk]

Thank you for the reply. I do have one more question. After sending a positive edge on the watchdog input, I just bring that pin to "LOW" until the next time I send out a positive edge, correct? Sorry if this question is very simple. For some reason I'm having a hard time understanding this.

 

[meBigGuy]

That will work fine.

 

[alphy]

To output a watchdog signal, you will need to follow the specifications outlined in the datasheet for the Infineon TLE4263-2ES voltage regulator. This includes connecting the external watchdog figure to the watchdog input pin on the voltage regulator and setting the appropriate timing and frequency for the signal.

In terms of the frequency at which you should send the signal, it will depend on the requirements of your specific application. The datasheet should provide guidance on the recommended frequency for the watchdog signal. It is also important to consider the timing requirements for the microcontroller and the voltage regulator to ensure proper synchronization.

You mentioned using a timer-based interrupt to send the signal, which can be an effective way to ensure accurate and timely output of the watchdog signal. Be sure to carefully program and test the interrupt to ensure it is functioning correctly and meeting the timing requirements.

In addition, it is important to understand the watchdog and reset information from the voltage regulator datasheet and to properly configure these features to fit your specific needs. This will help ensure reliable operation of your system.

If you have any further questions or need additional assistance, please consult the datasheet or reach out to the manufacturer for support. It is also helpful to consult with other engineers or experts in the field to gain further insights and guidance. Best of luck with your project!