Hi @Tim Edwards, I am trying to find the GDS layer number and descriptions for high voltage transistors (

sky130_fd_pr__nfet_g5v0d10v5

and

sky130_fd_pr__pfet_g5v0d10v5

). Through the

sky130A.tcl

file, I found their layers. Through the spreadsheet provided here (https://docs.google.com/spreadsheets/d/1oL6ldkQdLu-4FEQE0lX6BcgbqzYfNnd1XA8vERe0vpE/edit#gid=459375686) I found some layers corresponding GDS layer info. However, I am missing some other layers, such as

mvndc

,

mvpsd

, and

mvpsc

(just name a few), and I am not sure where to find their corresponding design rulesets. Any idea? Thanks.

@Chris the magic layer to gds layer translation is not straight-forward. The translation is encoded in the

$PDK_ROOT/sky130x/libs.tech/magic/sky130x.tech

file. See the

cifout

section. The easiest thing to do might be to display the gds layers (temporarily) in magic. Use

cif see <gds_layer>

.

cif see

by itself gives you a list of valid layers, I think. Use

feedback clear

to unsee the layers.

@Chris: The first tab of the spreadsheet you cited gives some of the magic-to-GDS layer mappings, although not a full set. It is probably worth making the effort to add another page to that document with a complete set of layer names and aliases in magic, and which GDS layers they correspond to. It's normal for a foundry to provide documentation of logic tables for derived layers, so I should do the same.

@Mitch Bailey @Tim Edwards Thanks for the info! While I am looking at the

cifoutput

section, I am under the impression that, in Magic there are multiple layers that are actually corresponding to the same GDS layer. For instance, I see the

DIFF

layer in GDS:

#----------------------------------------------------------------
# DIFF
#----------------------------------------------------------------

 layer DIFF 	allnactivenontap,allpactivenontap,allactiveres
 	calma 	65 20

Which is matching to

allnactivenontap

,

allpactivenontap

, and

allactiveres

, and I understand they are just the aliases to some other Magic layers. For example,

allnactivenontap

, is corresponding to all the following layers:

allnactivenontap *ndiff,*ndiode,*nndiode,*mvndiff,*mvndiode,*ndiodelvt,allnfets

My question is, how do you differentiate different layers in Magic if they are matching to the same GDS layer (such as both

ndiff

and

mvndiff

are

DIFF

in GDS. Also, I am wondering what is that

*

doing here. For example,

*mvndiff

. Thanks!

@Chris the

cifin

section of the technology file contains the rules for “mapping” the gds layers to magic layers.

@Chris: These are fairly standard definitions that have been in magic techfiles since the 1980s and work well with magic's database format. The most common derived layers are "ndiff", "pdiff", "nsc", and "psc"---These correspond to multiple GDS layers, as you noted, but you need to look through the whole cifoutput section to determine the combinations (if I don't provide you with a spreadsheet like I mentioned above would be a good idea). ndiff = DIFF & NSDM & !NWELL pdiff = DIFF & PSDM & NWELL nsd = DIFF & NSDM & NWELL psd = DIFF & PSDM & !NWELL

Thanks, @Tim Edwards and @Mitch Bailey, they are clear to me for now! That's a lot of work to put together all this info 🙂