Tips & Tricks – Allegro PCB Editor
Product Revision 16.3
Most likely your large pin-count nets are scheduled Min Tree. Add a voltage property or
RATSNEST_SCHEDULE = POWER_AND_GROUND to large pin-count nets like Vcc and GND.
Why does DRC Update take hours to run?
Usually the slower checking is a result of a large number of constraint areas and/or a large
number of overlapping constraint areas. If that is not the case, then it may be the larger spacing
values that you have to satisfy you high voltage requirements or simply fudge values entered as
no-ops. Large spacing values result in more neighboring items being examined for each item
** Review your extra large spacing values. I have seen the value of 999 entered on many
occasions. When reduced, DRC update went from 1 hour to 3 minutes.
Is my Database Optimized for Performance?
The performance advisor provides suggestions to increase database performance. The
command can be run from Tools – Database Check – Performance Advisor
Read Only Variables
A method for a site administrator to make variables read only
Add a “readonly” entry under the respective variable. In the example below, I wish to prevent
the end user from modifying PSMPATH. The command readonly psmpath is added just below
the "set psmpath" variable.