layer map and gds file writing

jnopaja

Hi Matthias,

I have a problem that I cannot find the answer.

I have a ruby script that is run through klayout [version 0.24.2 at the moment].

The script generates an RBA::LayerMap for an RBA::Layout. Then it reads in a file with data that corresponds to the layer map. When I write the information out, it appears that the layers are changing in the written file.

Example of the data:

The layerMap after initializing the layout and before any read operations have been performed:
10/0-63 : x
11/0-63 : y
12/0-63 : z
1/0-63 : a
2/0-63 : b
3/0-29,31-63 : c1
3/30 : c2
4/0-63 : d
5/0-63 : e
6/0-63 : f


The layout data after a RBA::Layout.read in (as output by the following code):
# get list of all layer indices of a layout
layer_indicies = @layout.layer_indices
layer_indicies.sort{|a,b| a <=>b }.each{|indx|
# get layer info for given index
layer_info = @layout.get_info(indx)
STDERR << "Layer::#{layer_info.to_s};#{layer_info.layer}\n"
# get shapes on layer index
layer_cell.each_shape(indx) {|shape|
STDERR << "Shape::#{shape};Index::#{indx}\n"
}
}

Layer::x;10
Layer::y;11
Layer::z;12
Layer::a;1
Shape::box (0,1500;1500,3000);Index::3
Shape::box (0,0;1500,1500);Index::3
Layer::b;2
Layer::c1;3
Layer::c2;3
Layer::d;4
Layer::e;5
Layer::f;6
Layer::136/0;136
Shape::box (1500,0;3000,1500);Index::10
Layer::136/63;136
Shape::box (1500,1500;3000,3000);Index::11


Then, after a write, I read the streamfile into a layout, and the layout has changed. Using the same output method as above:

Layer::x (10/0)
Layer::y (11/0)
Layer::z (12/0)
Layer::a (1/0)
Layer::b (2/0)
Layer::c1 (3/0)
Layer::c2 (3/30)
Layer::d (4/0)
Layer::e (5/0)
Layer::f (6/0)
Layer::136/0
Shape::box (1500,0;3000,1500);Index::10
Layer::136/63
Shape::box (1500,1500;3000,3000);Index::11
Layer::140/0
Shape::box (0,1500;1500,3000);Index::12
Shape::box (0,0;1500,1500);Index::12

The data in the newly written streamfile: layer a (layer 1, datatypes 0 and 63) data was written to layer 140 on the write. Any ideas on what might cause this?

Matthias

Hi,

Lacking a real testcase and the actual code I can only guess.

But I think what happens is that the mapping cannot produce a valid GDS layer since you map multiple datatypes to one layer. The effect is probably that the datatype number is undefined. If you print #{layer_info.layer} too you may see the datatype number is -1. Such layers cannot be written to GDS and a new number will be assigned.

To solve this problem you can try to map to a fully qualified GDS layer:

10/0-63 : x (10/0)
11/0-63 : y (11/0)
12/0-63 : z (12/0)
1/0-63 : a (1/0)
2/0-63 : b (2/0)
3/0-29,31-63 : c1 (3/0)
3/30 : c2 (3/30)
4/0-63 : d (4/0)
5/0-63 : e (5/0)
6/0-63 : f (6/0)

However, this will merge the datatype intervals into single datatypes.

Matthias

jnopaja

Ahh, after changing my layermap to map to datatype 0, it no longer produces the data on new layers and it correctly puts the data on the correct gds layer. I will attempt to solve our datatype issue, but I may have additional questions.

Thanks!