Intel E810-CQDA2T - Recovered Clocks (G.8261 Synce Support)

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Intel
®
Ethernet Network Adapter E810-CQDA2T
User Guide
4.6 Recovered Clocks (G.8261 SyncE Support)
Recovered clocks can be configured using a special sysfs interface that is exposed by every port
instance. Writing to a sysfs under a given port automatically enables a recovered clock from a given
port that is valid for a current link speed. A link speed change requires repeating the steps to enable the
recovered clock.
If a port recovered clock is enabled and no higher-priority clock is enabled at the same time, the DPLL
starts tuning its frequency to the recovered clock reference frequency enabling G.8261 functionality.
There are two recovered clock outputs from each of the C827 PHYs. Only one pin can be assigned to
one of the ports. Recovered clocks from Port 0-3 are assigned to C827 PHY0 and Port 4-7 to C827
PHY1. Re-enabling the same pin on a different port automatically disables it for the previously-assigned
port.
Note: In the current version, if you switch from a 1PPS clock to recovered clock (SyncE) you might
experience up to 200 ns deviation in the 1PPS signal.
1. To enable a recovered clock for a given Ethernet device run the following:
# echo <ena> <pin> > /sys/class/net/$ETH/device/phy/synce
where:
For example, to enable the higher-priority recovered clock from Port 0 and a lower-priority
recovered clock from Port 1, run the following:
# export ETH0=enp1s0f0
# export ETH1=enp1s0f1
# export ETH3=enp1s0f3
# export ETH4=enp1s0f4
# echo 1 0 > /sys/class/net/$ETH0/device/phy/synce
# dmesg
[27575.495705] ice 0000:03:00.0: Enabled recovered clock: pin C827_0-RCLKA
# echo 1 1 > /sys/class/net/$ETH1/device/phy/synce
# dmesg
[27575.495705] ice 0000:03:00.1: Enabled recovered clock: pin C827_0-RCLKB
# echo 1 0 > /sys/class/net/$ETH3/device/phy/synce
# dmesg
[27575.495705] ice 0000:03:00.3: Enabled recovered clock: pin C827_1-RCLKA
# echo 1 1 > /sys/class/net/$ETH1/device/phy/synce
# dmesg
[27575.495705] ice 0000:03:00.4: Enabled recovered clock: pin C827_1-RCLKB
Disable recovered clocks:
# echo 0 0 > /sys/class/net/$ETH0/device/phy/synce
# dmesg
[27730.341153] ice 0000:03:00.0: Disabled recovered clock: pin C827_0-RCLKA
# echo 0 1 > /sys/class/net/$ETH1/device/phy/synce
# dmesg
[27730.341153] ice 0000:03:00.1: Disabled recovered clock: pin C827_0-RCLKB
ena: 0 = Disable the given recovered clock pin.
1 = Enable the given recovered clock pin.
pin: 0 = Enable C827_0-RCLKA (Port 0-3) / C827_1-RCLKA (Port 4 -7) (higher priority pin).
1 = Enable C827_0-RCLKB (Port 0-3) / C827_1-RCLKB (Port 4 -7) (lower priority pin).