When the DP83TC813S-Q1 is active, the Signal Quality Indicator may be used to determine the quality of link based on SNR readings made by the device. SQI is presented as a 8-level indication. Signal quality indication is accessible through register 0x871. SQI is continuously monitored by the PHY to allow for real-time link signal quality status.

Bits[3:1] in register 0x871 provide SQI value while bits [7:5] provide the worst SQI value since the last read. The SQI value reported in register 0x871[3:1] map directly to the SQI levels required by Open Alliance.

To get the most accurate SQI reporting, use the initialization routine explained in SNLA389 application note.