Spread Spectrum Clock for Ethernet

[kamil_zorychta]

Hello,

Our platform based on I.MX6ull (Variscite DART 6ULL) with enabled 1 Ethernet port (of 2).

We would like to certificate our product, but we have got an EMC Ethernet issue.

During EMC tests we have observed 50MHz peak and its harmonics.

The disruption disappear when Ethernet went down (ifconfig eth0 down).

Is it possible to enable spread clock to Ethernet?

Best regards,

Kamil Zorychta

[igorpadykov]

Hi Kamil

>Is it possible to enable spread clock to Ethernet?

sorry not possible as only PLL2 has spread spectrum, ENET

PLL6 has not such functionality, this is described in Chapter 18
Clock Controller Module (CCM)

i.MX 6ULL Applications Processor Reference Manual

Best regards
igor
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[kamil_zorychta]

Hi Igor,

Thanks for answer.

So we will focus on pin configuration to smooth signals edges. It may help.

Best regards,

Kamil