Datasheet

 2017 Microchip Technology Inc. DS00002436B-page 21

KSZ8041TL/FTL/MLL

FIGURE 3-1: AUTO-NEGOTIATION FLOW CHART

3.9 MII Management (MIIM) Interface

The KSZ8041TL/FTL/MLL supports the IEEE 802.3 MII Management Interface, also known as the Management Data

Input/Output (MDIO) Interface. This interface allows upper-layer devices to monitor and control the state of the

KSZ8041TL/FTL/MLL. An external device with MIIM capability is used to read the PHY status and/or configure the PHY

settings. Further details on the MIIM interface can be found in Clause 22.2.4 of the IEEE 802.3 Specification.

The MIIM interface consists of the following:

• A physical connection that incorporates the clock line (MDC) and the data line (MDIO).

• A specific protocol that operates across the aforementioned physical connection that allows a external controller

to communicate with one or more PHY devices. Each KSZ8041TL/FTL/MLL device is assigned a unique PHY

address between 1 and 7 by its PHYAD[2:0] strapping pins. Also, every KSZ8041TL/FTL/MLL device supports the

broadcast PHY address 0, as defined per the IEEE 802.3 Specification, which can be used to read/write to a sin-

gle KSZ8041TL/FTL/MLL device, or write to multiple KSZ8041TL/FTL/MLL devices simultaneously.

• A set of 16-bit MDIO registers. Register [0:6] are required, and their functions are defined per the IEEE 802.3

Specification. The additional registers are provided for expanded functionality.

The following table shows the MII Management frame format for the KSZ8041TL/FTL/MLL.

START AUTO-NEGOTIATION

FORCE LINK SETTING

LISTEN FOR 10BASE-T

LINK PULSES

LISTEN FOR 100BASE-TX

IDLES

ATTEMPT AUTO-

NEGOTIATION

LINK MODE SET

BYPASS AUTO-NEGOTIATION

AND SET LINK MODE

LINK MODE SET?

PARALLEL

OPERATION

YES

JOIN FLOW