SNLS614A September 2018 – December 2018 DP83869HM
Near-end loopback provides the ability to loop the transmitted data back to the receiver through the digital or analog circuitry. The point at which the signal is looped back is selected using loopback control bits with several options being provided.
When configuring loopback modes, the Loopback Configuration Register (LOOPCR), address 0x00FE, should be set to 0xE720.
To maintain the desired operating mode, Auto-Negotiation should be disabled before selecting the Near-End Loopback mode. This constraint does not apply for external-loopback mode.
Auto-MDIX should be disabled before selecting the Near-End Loopback mode. MDI or MDIX configuration should be manually configured.