KSZ8893MQL-EVAL Micrel Inc, KSZ8893MQL-EVAL Datasheet - Page 54

• Manufacturer Part Number: KSZ8893MQL-EVAL
• Description: EVAL KIT EXPERIMENTAL KSZ8893MQL
• Manufacturer: Micrel Inc

Specifications of KSZ8893MQL-EVAL

• Main Purpose: Interface, Ethernet Controller (PHY and MAC)
• Embedded: No
• Utilized Ic / Part: KSZ8893MQL
• Primary Attributes: 3 Ports, 100BASE-TX/100BASE-FX/10BASE-T, Managed
• Secondary Attributes: MII, RMII, SNI, Auto MDI, MDI-X Auto Polarity Correction, LinkMD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-1603

Loopback Support
The KSZ8893MQL/MBL provides loopback support for remote diagnostic of failure. In loopback mode, the speed
at both PHY ports needs to be set to 100BASE-TX. Two types of loopback are supported: Far-end Loopback
and Near-end (Remote) Loopback.
Far-end Loopback
Far-end loopback is conducted between the KSZ8893MQL/MBL’s two PHY ports. The loopback path starts at the
“Originating.” PHY port’s receive inputs (RXP/RXM), wraps around at the “loopback” PHY port’s PMD/PMA, and
ends at the “Originating” PHY port’s transmit outputs (TXP/TXM).
Bit [0] of registers 29 and 45 is used to enable far-end loopback for ports 1 and 2, respectively. Alternatively, the
MII Management register 0, bit [14] can be used to enable far-end loopback.
The far-end loopback path is illustrated in the following figure.
December 2007
R X P /
R X M
Figure 12: Far-End Loopback Path
P M D /P M A
P M D /P M A
S w itc h
O riginating
L oop B ack
P H Y P o rt
P H Y P o rt
M A C
M A C
P C S
P C S
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T X P /
T X M
M9999-121007-1.5