Ethernet PHYs operate as either host or client when a network link is established. The host device uses a local clock to set the transmitter timing over the Ethernet port. The client device relies on the recovered clock from its received signal to set its transmitter timing operation. The DP83TD510 will resolve the Host-Client relationship through auto-negotiation when enabled.

The Host-Client configuration, as well as output voltage mode, can be set manually if auto-negotiation is disabled. The maximum cable reach of the PHY may be extended by forcing both the Host-Client relationship and output voltage operating mode. Specific cable characteristics may limit the reach of 10BASE-T1L’s low-speed auto-negotiation protocol by attenuating or distorting the DME over the channel. For example, a cable with high insertion loss around 625 kHz distorts the auto-negotiation pulses and the link partner may fail to complete the auto-negotiation process by not interpreting the received signal properly. Forcing the PHY into the desired mode of operation bypasses auto-negotiation and allows extended cable reach. The following configurations are offered by the DP83TD510E to enable "Force Mode". Please note, while using force mode, auto-negotiation shall be prevented by disabling MR_AN_ENABLE on both the DUT and link partner. Please see Table 3-3. One of the PHYs (DUT or link partner) shall be configured for host and the other for client.