To use external clock with spread spectrum for i.MX6 IPU/LDB.

[satoshishimoda]

Hi community,

I want to confirm the specification of i.MX6 PLL in CCM module.

Actually, I want to use a external clock with spread spectrum via CLK1_N/CLK1_P pin to IPU, LDB as following route.

external clock -> CLK1_N, CLK1_P -> PLL5(CCM_ANALOG) -> CCM -> IPU, LDB

In this case, I think spread spectrum is preserve if I set PLL5 to bypass mode by BYPASS bit (CCM_ANALOG_PLL_VIDEOn[16] in chapter18.7.11 of IMX6DQRM Rev.1).

Is this correct?

Or spread spectrum will be cancelled by PLL5 even if it is set to bypass mode?

Best Regards,

Satoshi Shimoda

[alejandrolozan1 · Accepted solution]

Hi,

As per the RM the System PLL or PLL2 is the one that features spread spectrum.

And it is different to the video PLL or PLL5. Therefore the spread spectrum should be preserved in case you want to bypass the PLL5.

Best Regards,

Alejandro