Fast Link Failure Indication - Renesas R-IN32M4-CL2 User Manual

R-IN32M4-CL2 User's Manual Gigabit Ethernet PHY Edition
2.4

Fast Link Failure Indication

The GbE-PHY exceeds IEEE 802.3 standards by indicating the onset of a link failure in less than 1 ms (worst case <3
ms). (IEEE 802.3 standard establishes a delay of up to 750 ms before indicating that a 1000BASE-T link is no longer
present.) A fast link failure indication is critical to support ports used in a synchronization timing link application. The
fast link failure indication works for all copper media speeds.
Caution: For all links except 1000BASE-T, the fast link failure indication matches the link status
register (address 1, bit 2). For 1000BASE-T links, the link failure is based on a circuit that
analyzes the integrity of the link, and asserts at the indication of failure.
R18UZ0043EJ0100
Mar 4, 2016
2. Functional Descriptions
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