topic Re: i2c transactions cause pwm glitches in Kinetis Microcontrollers

i2c transactions cause pwm glitches

nick_preiser — Tue, 19 Jun 2018 19:15:25 GMT

I am using a MKV11Z64VXX7, and all the very latest sdk components/libraries. (as of 6/19/18)

I have the device configured so that the ftms are being used to drive many independent pwm signals.

When I issue a periodic i2c transaction , the transaction is successful, however, I see a glitch on the

pwm signals.

Wondering if anyone else has see an issue

thanks

Nick P.

xiangjun_rong — Wed, 20 Jun 2018 09:46:41 GMT

Hi, Nick,

The PWM signal is a digital signal, it is normal that the PWM signal has undershoot and overshoot, I do not think it take effect on anything.

Hope it can help you

Xiangjun Rong

nick_preiser — Wed, 20 Jun 2018 14:44:28 GMT

I found that the issue only happens when I am using my jtag debugger, under sw debug.

Under normal operation, no issue. I am guessing that there is some resource sharing issue betwen the semi-hosting and the i2c/ftm/pwm...

I am going to close this for now. thanks Nick,