|
|
Magic Mailing List |
|
From: R. Timothy Edwards (tim AT stravinsky DOT jhuapl.edu) Date: Mon Apr 24 2000 - 10:35:42 EDT
Last week, I was trying to transfer an L-Edit layout into magic, and encountered the long-standing problem with contacts: This layout had a cell containing contact, metal, and active (CAA), which was used for n-diff, p-diff, n-well, and p-substrate contacts, and of course disappeared entirely on CIF read because for each contact type the layers ANDed into nothing. However, I was using the new SCN3M_SUBM.30.tech27 file, which contains entries for generic contact and generic active, and I made the following observation: if you simply add, to the top of the tech file "cifinput" section, the following lines: layer gc CCA,CCC labels CCC calma CCA 48 * Then ALL contacts become "gc" by default. All other contact definitions go after this one in the cifinput file, so that any contacts which meet magic's requirements by having all the right layer types in the same cell, will be overwritten with the correct magic contact type. The above definition will yield DRC errors, but it will actually be a complete and correct layout (although if you write CIF again from magic, CCA's which got turned into "generic contact" will get written out as layer CCC. . . would that be a problem?). At least this way, magic doesn't obliterate CIF geometry on input. Additional note: I made some other changes to the magic-7.1 source last week. I noted, on the same L-Edit layout, that magic will re-align anything not on the lambda grid without bothering to post any warning message that it has done so. I fixed this problem, and also added a "scalegrid" command, which changes the ratio of magic's internal units to lambda, so that by doing, for example, "scalegrid 1 2", magic units will be reduced to 1/2 lambda, and it will be possible to correctly read CIF files containing geometry on 1/2 lambda spacing without rewriting the tech file. This is a very simple implementation, and needs work, but it's a start. ---Tim
|
|
|
|