Stats

  • Locked Locked
  • Replies 8
  • Subscribers 127
  • Views 19711
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Creating circle in Virtuoso

zhengli
Hi, Can any one help me how to create a circle snapping to manufacturing grids defined in the technology file? I want to create a circle shape in virtuoso layout editor XL included in iCC 6.1.3. I found out that circle is actually created as a polygon. The problem is that when I export the layout into GDSII file, the ending points of the circle does not snapping to the manufacturing grids. I tried to create several real polygons, it is snapping to the grids. So I was wondering if there should be some additional setting to force circle shape snapping to grids. Please let me know if there is any solutions. Thanks a lot
Parents

  •  You will have to calculate the coordinates to get them to snap to the manufacturing grid. Calculate your angle based on the number of segments and that will give you the angle to calcuate each segment. Digging out your old trig book, sine of the angle is used to calculate the X value, cosine the Y value (the radius is the hypotenuse). Round the values to the manufacturing grid as you calculate them and you will get a slightly jaggy circle with everything on grid. You can do some smoothing after you calculate the points, adjusting the length of each segment independently.

     

    Ted

Reply

  •  You will have to calculate the coordinates to get them to snap to the manufacturing grid. Calculate your angle based on the number of segments and that will give you the angle to calcuate each segment. Digging out your old trig book, sine of the angle is used to calculate the X value, cosine the Y value (the radius is the hypotenuse). Round the values to the manufacturing grid as you calculate them and you will get a slightly jaggy circle with everything on grid. You can do some smoothing after you calculate the points, adjusting the length of each segment independently.

     

    Ted

Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.