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Port symbols - Safe to use "con_hier_i.1" and "con_hier_o.1" ?  (pin type confusion)

Question asked by bgreen5 on Aug 6, 2012
Latest reply on Aug 17, 2012 by olivier_arnaud

When migrating hierarchical schematics from DxD 2005 to DxD 7.9.3, DxDesigner automatically places required port symbols (and attached nets) on separate underlying sheets.  The "default" port symbols it places are from the 'builtin' partition from the standard install: in.1, out.1, bi.1.


Going forward (whether cleaning-up migrated designs or creating new schematics from-scratch), we had intended to standardize on a port symbol that was more appropriate from a design-review standpoint... something that was graphically more informative.


So, we had intended to use con_hier_i.1, con_hier_o.1, and con_hier_bi.1 (also from the 'builtin' partition).  We chose those for a couple of reasons:


1) The default ports (auto-placed during migration) look too much like traditional generic “physical” connector symbols (simple arrow)... too confusing

2) The “con_hier” (port) symbols are reminiscent in appearance to the older interpage (annotate) connector symbols, yet offer enough graphical distinction to inform users if they are using the correct symbol for hierarchical connection


We thought we were "good to go" in adopting the "con_hier..." port symbols, until some recent debug revealed an anomaly with their Pin Type properties.



SymbolPin TypeComments





Why opposite?





Why opposite?





(these match, as expected)




I am wondering if Mentor could provide any insight into why the "con_hier..." versions are different with respect to the Pin Type direction?  Our local AE has suggested that the symbol pin type (for the "con_hier..." versions) may be incorrect.


More importantly, is it safe to proceed with using the "con_hier..." symbols as ports... despite their apparently reversed Pin Type... ?  Or if we adopt them in their present state, will this cause problems for us down the road (e.g. DRC check errors, etc.)?


In my limited testing, there doesn't appear to be an issue... so far.


For example, if in the Special Components (speccomp.ini), I have defined my ports as follows...






... then, if I attach "con_hier_i.1" to a net called "alpha" and ensure the container block symbol pin named "alpha" has its direction defined as "IN", I don't seem to get any errors (despite the fact that this port symbol has a pin type of "OUT").


However, seeing this difference makes me a little nervous to proceed with the “con_hier...” symbols (for new/updated designs) without first understanding the potential consequences.  After a couple of years of fits and starts, we are about to embark on a widespread migration in earnest, and I wouldn’t want to have users implement defective symbols for port usage if it may cause us to have to revise schematics and re-train once again later on.