9S12 Configuring PMF's and Port P inputs

JamesonB — Tue, 17 Apr 2012 21:57:53 GMT

Hello,

I am using an MC9S12E128 in which the PMF module is on the P port. I am trying to enable only PMF4 and 5 on Port P while using PP0-PP3 as inputs. I'm aware that a peripheral takes prescidence over its corresponding Port I/O statements, however there is a line in the datasheet that states:

"The PMF function takes precedence over the general-purpose I/O function if the associated PWM channel

is enabled. The PWM channels 5-0 are outputs if the respective channels are enabled."

The Datasheet seems a little foggy on how to disable PMF channels and use them as inputs. Here is a snippet of my initialization code:

void Init_PMF(void)

{

PMFCFG0=0x5F; //Each pair of PMF's uses a different time base. A and B are edge aligned
// C is Center Aligned & are independent
PMFCFG1=0; //Positive polarity
PMFCFG2=0; //Unmasked
PMFCFG3=0; //PMF's run in 'Wait & Freeze' modes, No pair swapping
PMFOUTC=0x0F; //Enable software control of PWM pin
PMFOUTB=0x30; //disable PWM0-3

PMFENCC=0; //Verify that timer C for PMF4 & 5 is disabled
x=PMFENCC; //Read register prior to writing a 1 to the LDOKC bit
PMFENCC=2; //Write a 1 to the LDOKC bit

DDRP=0x30; //Enable PT0-3 as inputs, PT4 and 5 are PWM

}

I'm sure there is are quite a few 9S12 Guru's out there who have encountered this before or have some words of wisdom. I prefer to use the configuration mentioned above due to an existing PCB layout.

What is the proper way to configure the PMF3 and PMF4 peripheral and PT0-3 as Input pins?

Thanks,

Jameson

Re: 9S12 Configuring PMF's and Port P inputs

JamesonB — Fri, 04 May 2012 10:18:21 GMT

Well....I've figured it out. the key: Don't use device initialization like I was. For some reason, device initialization was trying to set up all of the PMF modules when I only needed Module C (i.e. PMF 4 and 5).

Thanks to anyone who looked into this. If anyone is interested in the solution, just request it.

Re: 9S12 Configuring PMF's and Port P inputs

ovek — Thu, 04 May 2023 07:55:18 GMT

I am trying to get all 6 PWM to work independently on a s12e on the PMF port P. Whithout any PMF-functionality activated. The PMF-init example I found didn't seem to work so any source-code example that you have about this PMF-module would be a help.

Best regards

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9S12 Configuring PMF's and Port P inputs

Re: 9S12 Configuring PMF's and Port P inputs

Re: 9S12 Configuring PMF's and Port P inputs