Why do some KSZ8851SNL devices fail to link upon a power cycle?

A slim percentage of KSZ8851SNL devices, when used in soft power down mode, may fail to link up during a power cycle. Soft power down mode turns off most of the clocks to conserve power, except the main clock. When the soft power down bit is cleared and the clocks are re-enabled, there is a small probability that the receiver block can enter a race condition where one of the Delay Lock Loop blocks lock onto the wrong phase of the main clock. This causes the received data to be sampled incorrectly and results in the device not receiving any data.

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