Spread spectrum feature for LCD clock

[yanissy]

Hi,

We performed EMC emission test and found that there is a peak at 204Mhz.

We suspect it is due to the LCD CLK.
We would like to check if there is spread spectrum feature for the LCD CLK?
If there is such feature, how can we enable it?

Regards,

SY

[igorpadykov]

Hi Foo

what processor used in the case, some examples can be found on

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/User-Guide-of-Spread-Spectrum-Support-fo...

https://community.nxp.com/t5/i-MX-Processors/i-MX-8M-Mini-Spread-Spectrum-Clock-MIPI-D-PHY/td-p/1168...

Best regards
igor

[yanissy]

Hi @igorpadykov 

We are using system-on-module VAR-SOM-MX7-5G from Variscite.

The processor is iMX7D.

We just got a reply from Variscite yesterday on how to enable the spread spectrum via CCM_ANALOG_PLL_VIDEO_SS and CCM_ANALOG_PLL_VIDEO_DENOM registers. 

We will try first using the information provided.

Meantime if you have example for iMX7D on this LCD spread spectrum, do share to us.

Appreciate that.

Regards,

SY