Kinetis MicrocontrollersのトピックRe: Reset pin : How to?

Reset pin : How to?

Jin — Sat, 19 Apr 2014 07:57:35 GMT

Dear Sir,

I am using "Kinetis KL24 :64-pin LQFP," but I've noticed the following problems.

In terms of the open state "RESET_b" terminal, about 1.5 ~ 1.7v about has been brought out.

This pin is in the input?

Why is the output?

In this case, the external reset circuit, connected to only the switch?

Meaning I do not know!

The correct, please tell me the reset circuit!

Best Regards,

Jin.

Re: Reset pin : How to?

Ben — Sat, 19 Apr 2014 19:20:02 GMT

Jin, it is normal to see a voltage there as there is a weak pull-up inside the chip.

Using this pin for RESET, freescale recommend to put an external pull up (4.7K-10K) and a small filter capacitor to ground.

I don't recommend to use switch only.

Re: Reset pin : How to?

Jin — Sun, 20 Apr 2014 00:26:03 GMT

Dear Ben,

Thank you for answer.

You have an external pull-up in 3.3v/10k but reset pin is the level of about 1.5v.

I'm debugging code Warrior, but this reset does not work decent factor.

I want to see the reset circuit!

Best Refards,

Jin.

Re: Reset pin : How to?

Jin — Sun, 20 Apr 2014 00:36:35 GMT

Additional Information: condenser is using the "0.1uF".

Best Regards,

Jin.

Re: Reset pin : How to?

Jin — Sun, 20 Apr 2014 07:27:05 GMT

Dear Ben,

Please let me know the specific value of "small filter capacitor to ground."

Best Regards,

Jin.

Re: Reset pin : How to?

Jin — Sun, 20 Apr 2014 07:28:17 GMT

Dear Ben

Dear Ben,

Thank you for answer.

You have an external pull-up in 3.3v/10k but reset pin is the level of about 1.5v.

I'm debugging code Warrior, but this reset does not work decent factor.

I want to see the reset circuit!

Additional Information: condenser is using the "0.1uF".

And.....

Please let me know the specific value of "small filter capacitor to ground."

Best Regards,

Jin.

Re: Reset pin : How to?

egoodii — Mon, 21 Jul 2014 22:19:12 GMT

If you are measuring this voltage on the !RESET pin with a voltmeter, you can be assured it is NOT a static condition, but is toggling between 'HI' and 'LOW' in a continuous reset-loop, most likely due to default 'watchdog on' activity (part not programmed properly--no valid reset vector?).