MPC5xxxのトピックQuestion about Leopard MPC5643L

Question about Leopard MPC5643L

pabloprieto — Tue, 12 May 2015 10:18:06 GMT

Hi guys,

I have a problem when I program my MPC5643L and is that all the DIOS get high level. I have two PWM that control two valves and when I program the MCU, the PWMs are activated. Any one knows if exist any configuration option to avoid this issue. I am working now in changing hardwardly the polarity of the signal, but this will be my last chance.

Any idea. Thanks in advance

Best regards

Pablo

Re: Question about Leopard MPC5643L

PetrS — Tue, 12 May 2015 14:09:12 GMT

Hi,

During and after reset almost all GPIO pins are in high-z state, until you configure the PCR registers, for example weak pull-down/up etc.

The PWM module control the output once the PA field in PCR register is set for PWM function and when PWM.OUTEN register is configured. In that case the polarity of the PWM output is done by PWM.SUBx.OCTRL[POLx] bits.

Regards,

Petr

Re: Question about Leopard MPC5643L

pabloprieto — Tue, 12 May 2015 14:55:52 GMT

Thanks Petr,

I will try with a pull down.

Regards,

Pablo

Re: Question about Leopard MPC5643L

pabloprieto — Wed, 13 May 2015 07:34:21 GMT

Hi Petr,

Are you sure that During and after reset almost all GPIO pins are in high-z state, because I'm trying with a pull down and it is not working, I always obtain high level.

Regards

Pablo

Re: Question about Leopard MPC5643L

PetrS — Wed, 13 May 2015 09:58:28 GMT

Hi Pablo,

The state of the pin can be checked against a Pin summary table of the device Reference manual (chapter 3.4; http://cache.freescale.com/files/32bit/doc/ref_manual/MPC5643LRM.pdf) and/or SIUL PCR register description (chapter 47.5.2.8).

Maybe the external circuitry connected to the pin pulls it high and weak internal pull-down is not enough to hold it down.

Regards,

Petr

Re: Question about Leopard MPC5643L

pabloprieto — Wed, 13 May 2015 10:31:33 GMT

Hi Petrs,

We have solved the problem. We were using very weak pull down. Now with an stronger one, it works perfectly, thank you very much for your support.

Best regards

Pablo