S32KのトピックRe: PLL calculation for S32k312

PLL calculation for S32k312

mogilipuri_harish — Thu, 16 Mar 2023 04:41:13 GMT

hello team,

i am using the S32K312 microchip in our design. can please help me to calculate the PLL output frequency. We are using 40 MHz external crystal oscillator. can you provide one example calculation? is it okay if you we are using 40 MHz crystal oscillator?

please provide the clock calculator for S32K312.

Re: PLL calculation for S32k312

Senlent — Thu, 16 Mar 2023 06:02:13 GMT

Hi@mogilipuri_harish

The FXOSC can be from 8MHz to40MHz,so the 40MHz crystal oscillator should be ok.

you can use "S32 Design Studio for S32 Platform" to set the clock tree.

for example:

PS:The S32K312EVB we provide uses a 16MHz external crystal oscillator

Re: PLL calculation for S32k312

mogilipuri_harish — Thu, 16 Mar 2023 06:59:15 GMT

hello senlent,

actually core clock frequency for S32k312 is 120Mhz.

Re: PLL calculation for S32k312

Senlent — Thu, 16 Mar 2023 07:13:01 GMT

thanks for reminding

In S32K312, CORE_CLK=160Mhz can still run, but it is not recommended for customers to use this way, there will be unknown risks

Re: PLL calculation for S32k312

mogilipuri_harish — Thu, 16 Mar 2023 10:00:05 GMT

here what are the variable values we can change??

Re: PLL calculation for S32k312

Senlent — Fri, 17 Mar 2023 01:06:36 GMT

Hi,

Didn't fully understand your question, do you mean which divider values can be changed?

these parameters in the picture can be changed, you can view these clock tree configuration in S32 DS.

Re: PLL calculation for S32k312

mogilipuri_harish — Fri, 17 Mar 2023 07:01:19 GMT

Fxosc = 16MHz

PLL = (16/2)*60=480MHz

POSTDIV = 480/2 = 240MHz

PHIO = 240MHz/2 = 120MHz

CORE CLK = 120MHz/1=120MHz.

Can you please verify the PLL calculation for 120MHz?

Re: PLL calculation for S32k312

Senlent — Fri, 17 Mar 2023 09:30:07 GMT

Hi,

for your reference,for example:

PLL output frequency must be in range:640MHz~1,28GHz.

Re: PLL calculation for S32k312

mogilipuri_harish — Fri, 17 Mar 2023 10:39:25 GMT

i am trying do this PLL clock calculation. can you given some notes how to do this calculation? like reference document. and i didn't find S32k312 example in tools, can you please share that it will be helpful to me.

Re: PLL calculation for S32k312

Senlent — Mon, 20 Mar 2023 01:25:21 GMT

Hi@mogilipuri_harish

Apart from the data sheet, there is no more guidance document for clock configuration

As shown in the figure,the version RTD 2.0.1 and above have routines for S32K312

Re: PLL calculation for S32k312

rekhak — Tue, 11 Nov 2025 10:37:38 GMT

Hi @mogilipuri_harish , were you able to resolve this issue. i am also dealing with same issue. i do have exactly same configuration , using MCAL 6.0.0 for S32K312.
facing error with "PLL ODIV2 = 2 " out of range