topic PLL values (i.MX8 plus) in i.MX Processors

PLL values (i.MX8 plus)

Zhaegar — Sun, 07 Dec 2025 21:06:42 GMT

Good Evening,

I am doing a bare metal boot & OS for the i.MX8 plus (MIMX8ML8CVNKZAB). Currently I can't find any values for things like 'PLL_MAIN_DIV' or 'PLL_MFREQ_CTL'. These bits are written to but there has been no explaination how they derived, I have ownly found Uboot abstracted data... If anyone can help that'd be great.

Re: PLL values (i.MX8 plus)

Zhiming_Liu — Fri, 12 Dec 2025 01:22:31 GMT

Hi @Zhaegar

The PLL formula from reference manual.

FOUT=((m + k/65536) × FIN) / (p × 2^s)

• Where, 1 ≤ p ≤ 63, 64 ≤ m ≤ 1023, 0 ≤ s ≤ 6, -32768 ≤ k ≤ 32767

Best Regards,
Zhiming