Answered: Watchdog Petting via SPI

VEX V5 Technical Support OFFICIAL Tech Support
1

Hi,

This is a post that was on the programming / technical area of the forum. Someone on that forum told me to move the message over heard to ask the experts.

I am really just interested in understanding how to do the min. to pet the watchdog so that I can use the user pic in assembly.

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I am guessing that the Master / User communications is done via SPI ( Serial Peripherial Interface ). I believe all that is needed to “pet the watchdog” would be to send some data to the master using SPI. The documentaiton is not specific but hints that getting the data ( getData function ) isnt what pets the WD.

The 18F8520 instruction set is simple I dont think it would be difficult to write a dissassembler for it that can provide symbols from the map file and flag symbols from the header / inc file. I downloaded a disassembler but sadley it doesnt cover the PIC18 family (PICDISLITE).

Whom might I speak to in order to obtain a copy of the master code that wouldnt require a watchdog update? This would really be better then attempting it myself?

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Thanks,
-Tom-

2

Unfortunately, we do not release Master Code.

3

Any chance you can look at the code and tell me what the parameters are to the SPI interface. If you want i can create a list of the parameters values I would need to know.

4

I can tell you that the watchdog is not use here, but you must do a Get Data and Put Data within a certain amount of time or the Master Processor will hold the User Processor in reset.