Question of drawing layout in Virtuoso

[Adam2008]

Hi Friends,

I got some question on drawing the layout in virtuoso:

1. The size of rectangulars(metals) can not be controlled as expected. Usually it will just match the size as the rectangulars already exist there, or it will match the corners of some rectangular. This is very weird.

2. The vias can only be placed on some specific posotion,. For example, the center of the via can only be placed on the corner of some rectangular(metal) .

3. Different metal layers can not have some overlap. If overlap, it will cover the whole area of the existing layer.

Anybody knows what could be the problem?

Thanks a lot.

Adam

 

[prashantbabu]

Hi Adam2008,
If I understand your problem correctly, I just suspect that you have kept the Gravity ON in your layout window. You can toggle it by pressing "g".
Hope it helps!

 

[Adam2008]

Hi, prashantbabu,

It works. Thanks a lot. Would you please also let me know what is "Gravity" for?


Adam

 

[fixrouter4400]

Hi Adam2008,

Hope this help you understand more.

Setting Gravity On and Off

You can use gravity to set the cursor (the small square) to snap to objects as you create them. This helps you create the edge of one object flush with another.

To set gravity on or off. Do one of the following:
-Press g to toggle gravity on and off.
-Set Gravity On in the Layout Editor Options form and click OK.

The cursor does not snap to objects on layers set to be unselectable in the Layer Selection Window (LSW).

 

[Adam2008]

I got it. Thanks again.

Adam

 

[kumar_eee]

I also faced this issue many times...

One more issue:

if ur caps-lock is ON, Layer selection/visible wont be possible by clicking middle button of the mouse in LSW window.