DRC rule deck writing

Which DRC tool are you writing the rule deck for? Pegasus? PVS? Assura? Diva? Dracula? Something else?

Andrew

I am using PVS.

Use the "negative1" option of the “exte” and “enc’ commands. This checks for the opposite of whatever constraint operator is used. If "equal to" is used, it will be treated as "not equal to".
 

exte layer1 layer 2 -eq 11.2 -output negative1;

enc layer 1 layer2 -eq 11.2 -output negative1;

Hi RobMan, I tried the above mentioned method, it's highlighting all the edges of the shapes other than the edges which are meeting the constraint, In good case, In my case I have used same layer shapes of two rectangles placed with space of 2, in this case the edges meeting the constraint is not highlighting, but highlighting other edges of the shapes. But this is a good case and should not highlight any edges, I need to highlight the spacing region if possible

Hi Thiruvenkata,

But that is what you asked for: "I can raise error if the value is less than specified constraint but I cannot raise error if the spacing is greater than specified constraint". i.e. You wish to flag shapes which are less than and greater than. BTW this is going to flag lots of shapes unless you have a specific structure with all uniform spacing.

So you want to flag spacing which are an exact value?

exte layer1 layer2 -eq 2.0 -output region;

What I wanted to convey is, I have two shapes separated by exact distance say 2, I have to write a rule that raise error when the spacing is either greater than 2 or lesser than 2, not equal to 2,  the method what you have written is working but what is the issue is the error highlighting section, even if I run the rule on the good case, its highlighting the other edges of the shapes. 

Yes, so you have two shapes: The space between the two shape is exactly 2.0. However, every other edge is not exactly 2.0 from another shape. So they WILL flag...

The top, left and bottom of the left layer1 shape are NOT exactly two from a shape on layer2.

This is why I raised a query on the validity of the check. Unless every edge of the layer1 shape is exactly 2.0 from a layer2 shape then an error will occur. The only sort of topology that would pass this check is like this...

Picture 1: Good case

Picture 2: Bad case

The above donut case is much useful, thanks for that.

If I am using same layer with two different shapes separated by a distance 2(Picture 1), I don't want PVS to flag the other edges, In case of bad case (the separated distance is not 2,  Picture 2), its flagging all the edges, its fine I guess.

Is there anyway to flag the region of spacing between the shapes that is not equal to 2?  

OK. But you do understand that in picture 1 the outside edges are indeed not exactly 2 from another shape.

So let's consider a real design:

  1) How many shapes of the relevant layers are you expecting to have?

  2) Are ALL of those shapes really going to be exactly separated by 2? (in ALL directions!)

  3) The edges are going to be a challenge, but I do have an idea how you might tackle that. However, if the answer to question 2 is "no" then there's probably no way to check this.

The only possible option would be to find shapes which are at some location on the periphery have a separation of exactly 2. However, Shapes like this will pass...

Do you consider the above legal? The separation is 2. But also there is a separation on <2 on the same shape. The outside edges fall into the same category as your piucture 1.

Thank you! Now I understood.