S32K中的主题 Re: FTM2 Output Modulation

FTM2 Output Modulation

bjrajendra — Thu, 07 May 2020 11:14:29 GMT

Hello all,

I'd gone through the thread FTM2 for Modulation & would like to understand more about the implementation of the same.

Can anyone help what exactly it mean using OUTSEL bits in SIM->FTMOPT1 help for FTM0 & FTM3 Modulation?

Does it mean it will help in the channel match with CH1?

if I keep SIM->FTMOPT1=SIM_FTMOPT1_FTM3_OUTSEL(0x01);

FTM2CH1 will give a modulated signal instead of channel FTM3CH0?

Clarify me in this regard.

Raju.

Re: FTM2 Output Modulation

bjrajendra — Thu, 07 May 2020 13:54:41 GMT

Hello all,

I got a question again.

Can anyone explain what actual the below lines explain?

Thanks in advance,

Raju

Re: FTM2 Output Modulation

Robin_Shen — Fri, 08 May 2020 08:07:16 GMT

Hi Raju,

It is difficult to describe in text, you can refer to the pictures in Modulated PWM waveform Generation

The Original waveform of FTM0_CH0~FTM0_CH7 should be like D0 D1.

The modulated waveform of FTM0_CH0~FTM0_CH7 will be like D2 D3.

The high frequency 50% duty PWM is FTM1_CH1.

Best Regards,

Robin

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Re: FTM2 Output Modulation

bjrajendra — Fri, 08 May 2020 11:43:58 GMT

Hi Robin,

Thanks again for your swift response.

I have few questions.

1. Is FTM2 generating a 50% duty modulated signal?

2. In the case of modulated frequency i.e, D2 & D3, how actually channel duty cycle is varied?

3. Is there anything we need to do via hardware so as use FTM2 for modulating frequency?

4. Can you share an application note or code for describing such a scenario?

Thanks in advance,

Raju

Re: FTM2 Output Modulation

allen_willson — Mon, 11 May 2020 18:00:48 GMT

Let me try to add comment to your questions.

1. It generates a 50% duty cycle pwm output. The FAULT input signal performs the modulation.

2. Same as usual for PWM functions. MOD register is the period and CnV register is the duty.

3. Yes, you must hard wire the FTM0 outputs (ch0 and ch2) to the FTM1 and FTM2 FAULT input pins

4. Code was shared on the post which Robin referred: https://community.nxp.com/thread/450366

hope this helps.