Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Configuring triple speed ethernet MAC with National DP83848 PHY in MII interface

Hi I am trying to make a design with a triple speed ethernet MAC from Altera work. I am using a National DP83848 PHY and the small 10/100 version of the MAC. I have attached a snapshot of my sc...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

I had the same heat problem and it turned out my VCCIO levels was accidentally wrong. Make sure the 1.8V, 2.5V and RC filtered supplies are all correctly configured, and especially that the VDD_SEL_STRAP pin is correspondingly strapped to your VCCIO.

Are all these rails the correct voltage? Especially the RC-filtered pins, are they still 1.8V? If those pins draw excessive current there will be a larger voltage drop across the resistors.

Do the chips actually work or are they dead? When operating in GB mode they do get quite hot, but otherwise they're only moderately warm.