topic Re: What does Software Watchdog & Hardware Watchdog means in the K series? in Kinetis Microcontrollers

What does Software Watchdog & Hardware Watchdog means in the K series?

trannamson — Tue, 09 Sep 2014 08:58:48 GMT

Dear community members,

I'm working with the Kinetis K series Product Update Report (KPUR). There are two kinds of watchdog is written : Software Watchdog and Hardware Watchdog.

However when I check out the Reference Manual such as MK70FX512VMJ15, There are two kinds of watchdog in different name : External watchdog monitor (EWM) and Software watchdog (WDOG).
I consider External watchdog monitor (EWM) is the Hardware Watchdog which is written in KPUR but I'm confuse if it was correct or not.

Does anyone give me a lecture to clearly understand about this?
Thank you!

Re: What does Software Watchdog & Hardware Watchdog means in the K series?

Kan_Li — Wed, 10 Sep 2014 02:34:01 GMT

Hi Nam,

In my understanding, EWM is used to monitor the enternal peripheral while WDOG is used to monitor the embedded software flow and execution, the main difference between them is EWM does not reset the MCU's CPU and on-chip peripherals, it has an independent pin to assert reset or place an external circuit into safe mode when EWM is allowed to time-out.

Hope that makes sense,

Have a great day,
Kan

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Re: What does Software Watchdog & Hardware Watchdog means in the K series?

trannamson — Wed, 10 Sep 2014 09:05:28 GMT

Hi Kan,

Thank you for pointing out the difference between EWM and WDOG. I've checked the Reference manual and get what you mean.
But what I confuse is the meaning of Hardware Watchdog. And how difference between Hardware Watchdog and Software Watchdog?

Thank you and have a great day,

Tran.

Re: What does Software Watchdog & Hardware Watchdog means in the K series?

Kan_Li — Thu, 11 Sep 2014 06:35:51 GMT

Hi Tran,

In my understanding, they are both hardware modules on the chip, the main difference is their usage, EWM usually monitors the external hardware, while WDOG monitors the embedded software.

Have a great day,
Kan

Re: What does Software Watchdog & Hardware Watchdog means in the K series?

trannamson — Fri, 12 Sep 2014 07:15:55 GMT

Hi Kan,

Thank you for your advise!

Best Regard

Tran.