Dear Expert,
RGMII protocol version2.0 defines the requirement of RXC and TXC clock is +-50ppm as below show, and also I found the requirement of PHY crystal is +-100ppm.
My questions are:
- Why the PHY crystal tolerance are larger than RGMII clock requirement?
- Why PHY has crystal requirement 100ppm
- How does the requirement(PHY crystal +-100ppm) conclusion come out:
- Why RGMII requires +-50ppm on RGMII?
- If we use 100ppm crystal for PHY, then what is the risk between RGMII communication?
RGMII protocol:
DP83TG720R datsheet:
