Implicit pwr/gnd in Eagle Layout

Archive BatchPCB
1

Hey all,

I’m new here, so hopefully I posted this in the correct forum. I’ve been searching all day for the answer, so hopefully somebody knows how to fix this. A buddy and I are working on an MP3 player for a microcontroller project in one of our engineering design classes. We decided to use an AT89C51SND1C from Atmel because of its MMC interface and MP3 decoder built in.

Yesterday we designed the hardware, made the schematic in Eagle, and we just finished the layout, however we are stumped about the implicit power and ground lines. The uController we are using has the following power and ground lines, VSS, VDD, UVDD, UVSS, PVDD, and PVSS. We figured out that by using the VSS and VDD symbols and connecting them to our +3V3 and GND nodes that our VSS and VDD nodes on the uController would be reassigned to the +3V3 and GND nodes.

Our problem lies with the rest of the implicit power and ground nodes. Neither of us are familiar with the Eagle software, and we are not sure how to assign the UVDD, UVSS, PVDD, and PVSS to the +3V3 and GND nodes.

I hope that this post wasn’t too confusing, if anyone can help us out, it would be much appreciated.

  • Mike
2

if the power/gnd pins are not on the lib part you placed, select edit/invoke and left click the part. It should give you a dialog that allows you to select and place the power pins. at least that’s how all the 74xx logic parts work.

3

Philba,

Thank you I believe that is exactly what we are looking for :slight_smile: