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Implement Watchdog Driver for familly 14h(bobcat)

Question asked by destrif on Sep 24, 2015
Latest reply on Sep 25, 2015 by jtrudeau



I am currently a new driver developer.

I have to implement a watchdog for a card having a bobcat CPU.


First I need to understand what the watchdog is able to do? Why is there 2 watchdog(CPU,NorthBridge)?

Why would I have to start them at the same time? and why with a higher time count value in NorthBridge?


My mission is to implement a basic watchdog which count down to zero. And if it reach zero it restart the card.

Is it possible to do it with this CPU?(Most important question)


Finally, I have trouble to access the region of:

Device 0 Function 0 (Root Complex) Configuration Registers


I can access the register: cf8, and cfc.

I am also able to access the MSRC001_0058 modele special register.

But after what should I do with it?access the base address given in memory?

And after that: set the address[31:0] with my good information(D18F3x40)?

But at the end after setting the good information in address[31:0], where will I read the data contained in that address??


MMIO configuration: configuration space is a region of memory space.
• The base address and size of this range is specified by
MSRC001_0058 [MMIO Configuration Base

Address]. The size is controlled by the number of configuration-space bus numbers supported by the sys- tem. Accesses to this range are converted configuration space as follows:

• Address[31:0] = {0000b, bus[7:0], device[4:0], function[2:0], offset[11:0]}.




The documentation for 14h family is given here:



Thanks a lot in advance for your time!


Sincerely Yours,