Ethernet DP83848 not working

With the default configuration, the speed LED should be lit. This is because the speed LED indicates 100Mbps functionality and in Auto-Negotiation mode, the 100Mbps receiver is active.

For what PHY address is the PHY strapped? Is the MAC reading from the same address? On a read from the PHY, what data is read back? If you put a scope on the MDC/MDIO signals, what do you see?

Patrick

PHY strapped means what?

how will be output mdc/mdio signals

jaya

Jaya,

Strap is short for bootstrap. These are dual use functional pins that are used for device configuration at power up and during reset. The datasheet section on pin descriptions includes a section on strap options.

The datasheet also includes a section on MDC/MDIO. This interface is referred to as the Serial Management interface. MDC is an input to the PHY and should be driven by the MAC. MDIO is a bi-directional I/O.

Patrick

hello

when i connect my mcb2300 development board,reading registers are ok
connection establish is auto nego, 100Mbps, Full duplex. LED LINK, ACT are glowing in this board when i connect to PC

but when i connect my custom board, connection establish is auto nego, 100Mbps, Half Duplex
since led link , led act are not glowing even after connecting to PC

Connection between dp83848 and pusle transformer HX1188NL is my doubt.
Connection between HX1188NL and RJ45 connector is my doubt.
can u suggest the connection and check points at pulse transformer


jaya

Hello Jaya,

A few questions:

What address is strapped on the PHY? Is your custom board MAC reading from the same address? What do you get when you read register using the custom board?

Please refer to the schematic below as a reference for PHY, Magnetics and RJ45 connections.

For more layout related questions you can refer to the following 'Design and Layout Guide' application note: http://www.ti.com/lit/pdf/snla079

-Regards,

Aniruddha