MPC5xxxのトピックRe: about FlexPWM

about FlexPWM

motman — Wed, 27 Jan 2016 08:57:44 GMT

Dear all.

Hi. I'm studying FlexPWM about MPC5643L.

I can't understand OUT23 and PWM23. In reference manual, I can select that using Deadtime Source Select Register(DTSRCSEL).

I understand that PWM23 is generated from comparing counter register(CNT) and value register(VAL2, VAL3).

But i can't find how OUT23 is generated.

And i don't understand deadtime logic.

Can you explain this?

Thanks.

Juhyung

Re: about FlexPWM

petervlna — Wed, 27 Jan 2016 12:03:32 GMT

Hi,

The OUT23 and OUT45 are implemented to device so user can select the level of signal during deadtime.

OUT23 bit is only used when SEL23 for submodule 0 is set to 0b10. It allows software control of which signal is supplied to the deadtime generator of that submodule.

1 = A logic 1 is supplied to the deadtime generator of submodule 0 instead of PWM23 or PWM45.

0 = A logic 0 is supplied to the deadtime generator of submodule 0 instead of PWM23 or PWM45.

The SEL23 and SEL45 fields each choose from one of four signals that can be supplied to the submodule outputs.

So if your SEL23 is configured for OUT23 then on the module output you will see the signal according to SWCOUT register configuration.

Re: about FlexPWM

motman — Fri, 29 Jan 2016 04:04:56 GMT

Dear Peter.

Thank you for your reply.

You mean that SWCOUT register select OUT23 or OUT45 value. Right?

SWCOUT register control output as Force out. I don't know what i think.

And, Can you have a PWM capture example? If you have, can you explain how can initialize, how can use.

Thanks.

Juhyung.

Re: about FlexPWM

petervlna — Mon, 01 Feb 2016 11:59:33 GMT

Hi,

OUT23 -> PWMA of selected submodule - It allows software control of which signal is supplied to the deadtime generator of that submodule.

OUT45 -> PWMB of selected submodule - It allows software control of which signal is supplied to the deadtime generator of that submodule.

Peter

Re: about FlexPWM

PetrS — Tue, 02 Feb 2016 11:48:25 GMT

Hi,

refer to the attached example. The Submodule0 is set to generate independent PWMA and PWMB signals. The PWMX is used as input for the Capture feature.

Capture logic is set to capture one rising and one falling edge in one shot mode. Thus you can check the edge placing and calculate a generated duty cycle.

BR, Petr