The 3Di file can contain a table of rules that will be used by the DRC module for checking wire-wire spacing, wire to substrate spacing and wire to conductor spacing. This section begins with:

  DRC_RULES 

Each rule must be assigned an integer to track it.

  RULE <number> 

After assigning the rule an integer, the next line assigns the rule type, the number of inputs to the rule and the DRC parameters to enforce.

  <rule_type>  <num_inputs> <drc_parameter> 

Each input must be on its own line and describes a geometry type, layer and net. (in the future, more properties can be used as rule inputs ...)

  <input_type>  <layer> <net> 

After all of the inputs are listed, the DRC marker for this rule is defined. It can be any 3Di geometry but conventionally it is a sphere.

  <marker> 

Example of Wire to Wire Spacing Rule

DRC_RULES
RULE 1
SPAC 2 0.25
WIRE 0 0
WIRE 0 0
GEOM 30 0 0
SPHE 0.0 0.0 0.0 0.05 12

Explanation - RULE 1 is a spacing rule (SPAC) with 2 inputs and the spacing value = 0.25. The first input is a WIRE on layer 0 (i.e all layers) with NET 0 (i.e. all nets) and the second input is a wire on layer 0 with NET 0 (i.e. all nets).

The marker that should be used to highlight violations to this rule is a GEOM of type SPHERE with color 30 (net and layer = 0) The sphere is placed right on the error location (0,0,0) and has radius 0.05 and is approximated using 12 sides.

Placing Rule Violation Markers

When a 3Di file is initially produced from the layout tool, there will not be any Rule violation markers present. After the DRC module is run, it will create such markers in a section called DRC_MARKERS.

Each marker is on a single line and references the DRC rule that has been violated, the value which generated the violation and the coordinate where the violation was deemed to have occured.

MARK <rule_number> <drc_value> <x> <y> <z>



DRC_MARKERS
MARK 1 0.22 0.56, 0.43 1.77

Explanation - RULE 1 is violated - the spacing value is measured at 0.22 (when the limit is 0.25) and it occurs at x,y,z=0.56,0.43,1.77