Article ID: 000075614 Content Type: Troubleshooting Last Reviewed: 11/15/2011

Late Collision in Half-Duplex 10/100-Mbps Ethernet MAC

Environment

    Quartus® II Subscription Edition
    Ethernet
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Critical Issue

Description

MAC function with 1000BASE-X/SGMII PCS may detect late collision when it is operating in 10/100-Mbps half-duplex mode. The external third party PYH and cables introduce latency in addition to the latency of the 1000BASE-X/SGMII PCS with embedded PMA. This issue arises when the total latency exceeds the 512-bit slotTime as defined in IEEE 802.3 Clause 4.4.

This issue affects MAC function designs that contain 10/100/1000 Mbps Ethernet MAC with 1000BASE X/SGMII PCS operating in 10/100 Mbps half duplex mode.

Resolution

Use 10/100/1000 Mbps Ethernet MAC only with GMII/MII or RGMII for 10/100 Mbps half duplex mode operation.This issue is fixed in version 11.0 of the Triple Speed Ethernet MegaCore function.

Related Products

This article applies to 1 products

Intel® Programmable Devices

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