I changed schematic connection (in schematic editor) while drawing layout. 
Layout editor does not seem to notice the changes and an error is reported 
(wrong connection - yellow cross on the connecting metal path - short 
marker).A had this issue before, and it is pretty likely that LVS will 
fail, although schematic is OK. How to make layout editor update after 
making changes in schematic editor and not to draw short marker?

Your question is a bit unclear, so let me take a guess. If using Layout XL 
(or VLS XL in IC61), then you would need to do Connectivity->Update 
Components and Nets (and potentially a "check" operation on the schematic 
if you've not done so already). This doesn't happen automatically (because 
it would be really annoying to have it change half way through doing the 
layout, if you wer e only half way through making the schematic changes...).

I'm having trouble getting the update components and nets function to work 
as I expect in Layout XL. I'm creating several flavors of a ring oscillator 
and instead of starting from scratch I copy the layout over from the 
previous instance and use the update components and nets function to add my 
new devices. I insert them in the chain where they appear in the schematic 
but the final node name doesn't update for some reason. For example the 
output of the first ring oscillator is named osc. All of the subsequent 
versions are still labeled osc even after doing a 
Connectivity->Update->Update Components and Nets with the Update Nets and 
Instance Name Mismatches Only option. This is really just an annoyance as 
the cell will LVS/DRC clean but I don't understand why this doesn't work. 
I'm using IC 6.1.7-64b.

I found that if I remove the instance(s) that the net in question is 
connected to and re-instantiate it this issue is fixed. I went ahead and 
made the changes in each cell but this was a rather inconvenient brute 
force fix. I think there must be a more elegant solution I'm missing.

The best way to do this is to use Connectivity->Update Binding. Set 
preserve existing bindings to be on (so that you don't change any existing 
bindings), and also turn on clear connectivity. This will remove any 
existing logical connectivity, including any "sticky" nets. That should fix 
the net names.

I want to enable the same effect on the cyclic option between schematic and 
layout. For example, when selecting a device in the schematic, it is 
selected in the layout. I want the selected object in the layout to get 
this dimming effect. However, it is better to be enabled only if the 
devices selected from the schematic. Because, sometimes it is hard to spot 
the selected devices in the layout, so the dimming effect would help in 
this.

Which version are you using? I just checked in IC6.1.8 ISR14 (so it would 
be the same in ICADVM20.1), and just turning on "Enable Dimming" on 
Options->Display in the layout editor does what (I think) you want (I have 
Scope set to "none" - the default). If I select something in the schematic, 
the corresponding instance is selected on the layout side, and everything 
else is dimmed. The cdsenv var you refer to corresponds to the "True Color 
Selection only" checkbox in the dimming section - if turned on, then that's 
equivalent to that env var being nil (it means it doesn't draw a highlight 
around the selected instance).

Thank you Andrew very much. It is working as you described. I'm running 
IC6.1.7. Can this dimming effect be enabled only for devices and nets 
selected from schematic? In regular selection for moving, I don't want the 
dimming to be enabled.

Hello (again)! I recently switched to IC 6.1.7, and now I am unable to get 
the QuickAlign layout command to align the center point of an object to the 
"edge center" of another object (as I could easily do in IC 6.1.6). 
Moreover, when I press F3, the dialog I get for the QuickAlign command 
options looks rather different (i.e. many less options) than the one shown 
in the documentation. Do I need to configure/activate something somewhere 
else? or maybe it is broken due to an incompatibility with my design kit 
with this new version?

I suspect that maybe you just need to use the Right Mouse Button menu to 
control quick align. I just tried an align from the centre of one object to 
the edge centre of another object, and that worked OK. I did have "points 
and edges" enabled on the quick align mode - the right mouse button menu 
gives you the option to switch to edges only (and if that has been 
selected, the menu offers to switch you back to points and edges). My guess 
is that maybe you're in edges only mode?

Hi Andrew, thanks so much for your prompt reply. I in fact thought 
initially it was the "Snap to edges" option being enabled, but I after 
checking again the problem persists. What's more, I really get fewer 
options than what described in the documentation (I checked the guide for 
version 6.1.7). Here is a snapshot of what I am getting:

As you can see, when I point to the edge center of the target object I get 
the yellow DOT and not the (small vertical yellow) LINE that would allow me 
to only align vertically both rectangles (and not to actually move the 
center of the origin object to the edge center point of the target object, 
as would happen in the example above).

You can upload pictures using the Insert/Edit media buttons in the rich 
text editor when posting - these are in the middle on the bottom row of 
buttons (between the right indent and the Paste from Word button).

Anyway, I think you can do what you want. Click the centre of the first 
object (which you've done) and then move slightly away from the edge centre 
and it should highlight the entire edge. Or, after clicking on the centre 
of the first object, do Right Mouse and change to edges only and then 
you'll only be able to select edges as the target. I think this was done to 
make it clearer whether the target is an edge - before it sort of showed 
you it as both a point and an edge, and it probably wasn't obvious which 
would win.

Ah, maybe I understand what you mean. I tried in IC616 and you could move 
slightly away from the edge and end up with a target alignment "edge" 
perpendicular to the actual edge. I'll add a picture (I'll have to edit the 
post because I'm writing this in a browser that doesn't reliably work with 
the insert media button - turns out it is currently not working in the 
other browser I was using too on my platform - so here's a link to the 
image instead) to show what it looks like in IC617 if I move away from the 
edge. Is this what you mean? I can't see how to do this in IC617 - I 
suspect something has broken.

Exactly!!! That's what I am talking about! That small edge that would allow 
(whenever the point in the origin object is the centerpoint, I think) to 
align only in the X or Y dimensions, leaving the other unaffected. I guess 
then it is some kind of bug in IC617. Could you please also confirm if the 
F3-options and context menus that you get are like the ones I am seeing?

Yes, the RMB menu and F3 options forms are as expected. They've been 
streamlined in IC617, and this is not a PDK-related issue. This doesn't 
appear to be anything to do with options on the forms - something has 
changed.

When I try to draw a path or move any object in the virtuoso layout XL 
window, I am able to do so only in steps, as in the pointer moves in steps 
and thats why I am not able to draw anything to an exact precision.

When I do top level layout in XL and try to show all incomplete nets, I do 
see flightlines come up but not ALL OF THEM. I did 
connectivity->update->extract layout, but it did not help. I noticed that 
when I move some of the sub blocks off a little bit, some more additional 
flightlines coming up, then when I made some routing at the not-shown 
flight lines, at these places, flightlines start showing up again.

Starting at some time (do not know when/why) doing a fit does fit the 
layout in the middle of the layout editor, but there is a huge black area 
around it. So the size of the layout (rectangle form) shown is

But: I (and my colleagues) have checked for such things about 100 times 
(including changing the visability and selectivty of layers, changing the 
shown layers at the Techfile, marking & deleting everything outside the 
block, ...). We are absolutely sure that there is no device left outside of 
the instance's boundry!

I'd like to select some pins so I can move them. However, clicking on them, 
whether in the layout, navigator, or schematic, does not select them in the 
layout. All layers and objects are set to be selectable in the palette. 
What am I doing wrong? I'm using IC6.1.7-64b.78.

There is an issue where bounding boxes are wrong - but that doesn't seem to 
be what you're describing: Reason for cell's large-sized boundary or 
bounding box aka bBox area or extent of layout. SKILL to delete steiners, 
markers, guides, remove invisible ghost layers, shapes.

I tried with the Dynamic Selection Assistant, it does not show anything 
when I hover my pointer on this box both in the original layout and when I 
instantiate it.

I unchecked 'Valid' in the layers panel setup but I still do not see the 
box.


I will check your link.

I'm guessing the white line in your picture above might just be because 
you've selected the instance? If so, it could be objects in the underlying 
cellView. That is usually obvious if you open the underlying cellView and 
try fitting to the cellView and you end up with a lot of space around the 
layout - the article I mentioned should help in that case (probably) if 
it's not a real (but invisible) layer.

I have a basic issue, in the layout design I need to creat a group of some 
implemented devices, example I want to make the differential pair matched 
transistors as a one group after I have layouted them, so I can move them 
safely as a one device.

That's only for when you want to add to an existing group. Instead select 
the objects you want and do Create->Group, or if nothing is selected you 
can do Create->Group, select the objects (as prompted) and then either 
Apply the popup form or hit Enter.

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