Encounter DEF file export

 Hi Kari,

So there is no mapping table between GDS2 layer type and Encounter layer type? such as NET in encounter should be drawing in DFII, SPNET in encounter should be drawing in DFII as well?

Also, after I create mapping file for encounter, the only way to confirm it's right is by checking the layout shown in DFII is same as layout shown in encounter? it sounds too dangerous if the layout is big and complex.

In addition, I tried to export gds2 from encounter to DFII, then calibre DRC shows text label error, it seems related to NAME layer in encounter mapping file, how to match the layer data type for this?

Thanks a lot!

James

 Hi James,

In general, yes - NET and SPNET would map to the drawing purpose, but PINs may also, or the DFII map may have a separate PIN purpose. Metal fill may map to drawing or some other purpose. There's just no guarantee that everyone does the same thing in their DFII map file. Like I said, I've seen some weird DFII gds maps! 

As for confirming it's right, it's not as trial-and-error as it may have sounded. The layers and object types in Encounter are not that many - when you create your Encounter map file, you can be pretty sure you're getting everything. It's just good to verify a few things after you stream in to DFII. Also, some people output text, some don't, etc. I just want you to make sure you're getting everything you want. You don't have to pore over the entire layout! Just check a few signal routes, a few power routes, a few pins, etc. to make sure that type of data got translated correctly. Your signoff DRC and LVS would be the final test.

I'm not sure what your Calibre text label error is. Do you mean the text is not on the layer that Calibre is expecting? You may need to check the Calibre deck with the DFII gds map to make sure that matches first. Most DFII map files have a "text" datatype, but again, it can vary. Then double check that the DFII map matches the Encounter map. Yes, the NAME lines are the ones that deal with text.

- Kari

 Hi,

 Nowadays, it is difficult to explain we still use DEF/LEF format to exchane design. Most of people, especially EDA tool sellers, want we use all of their methodology (OpenAccess, GDSII, and another complicated and dark format which are not as easy as the "old fashionned" but reliable DEF....)

 I prefer, as you, these methodology (based on DEF), because it is easier to debug, net/instance names are respected, verilog and layout are well aligned along the design flow, and it's better to map RC extract, on DEF, with verilog Name etc...

 So, if you want to export Via LEF definition in your Defout with Encounter, you may switch to 1 the variable defOutLefVia   (in encounter, before defOut, you put "set defOutLefVia 1"  or through the gui, Design->Global Variables)

 You'll have the via defined as same as in the LEF file at the begining of the DEF file. A problem could appear if your technology is not aligned between Virtuoso (DFII techfile --editable --) and Encounter (LEF technology), concernig the array of Via...In case of mismatch, they will be created in the library for DefIn, as instantiated cell (and not as ViaArray generated from technology library) But you'll have your design, and their via.

It could avoid all of workAround to preserve instance names, or net name in another format...

 BR

Haf.