Connector Loopback; Figure 2.5 Connector Loopback Diagram - Renesas R-IN32M4-CL2 User Manual

R-IN32M4-CL2 User's Manual Gigabit Ethernet PHY Edition
2.5.4

Connector Loopback

The connector loopback testing feature allows the twisted pair interface to be looped back externally. When using this
feature, the PHY must be connected to a loopback connector or a loopback cable. Connect pair A and pair B, and pair C
and pair D, as shown in the following illustration. The connector loopback feature functions at all available interface
speeds.
MDI

Figure 2.5 Connector Loopback Diagram

When using the connector loopback testing feature, the device autonegotiation, speed, and duplex configuration is set
using device registers 0, 4, and 9.
For 1000BASE-T connector loopback, additional writes are required in the following order:
1. Enable the 1000BASE-T connector loopback. Set register bit 24.0 to 1.
2. Disable pair swap correction. Set register bit 18.5 to 1.
R18UZ0043EJ0100
Mar 4, 2016
A
B
PHY_port_n
C
D
RXD
MAC
TXD
2. Functional Descriptions
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