cadence layout problem

[jlim]

hello,
i am new to analog cadence design..i want to ask is it the cadence can automatic layout from the schematic that we draw..??how to carry out it..??
Can somebody teach me..??
Thanks~~~

 

[gradha]

yea... we can do the automatic layout using schematic... Below i will mention few requirements just check whether are they available in your system ...

1. Need to have XL or GXL licences.
2. When u open ur layout window using these u will find "Place" and "Route" options.
3. Need to have schematic_XL.
you will find all these under "Launch".

If u have these, u need to know something about constraint manager so that u can define constraints in schematic as per requirements. u will find these in VIRTUOSO DOCUMENT.
then after defining the constraints as required . Open layout_XL or layout_GXL and u will an icon at left bottom corner saying "GENERATE FROM SOURCE" (only in layout_xl and layout_gxl) if u press a pop up appears check the window and press ok when everythings fine with that popup. Now u will see all the components in the layout field.

Now, check for Place icon on the menu bar and from dropdown select automatic place and press ok. Ur placement is done and now find out Route from the menu bar and from dropdown select auto route and find whether all the options in it are fine and press "ok" ur routing will be done. Make sure whether all ur routes are done because some times few nets will not get routed and also there will be shorts in the layout. Check them out .

Go for auto route only when there is an ample of time with u, for the first time it will take ages to do but once u get familiar with it it will be very easy one and once u get familiar with it it will copmplete a 150 * 150 microns area block in 1 hr. where normally it will take one day with all kinds of current mirrors and Differential amplifiers in the circuit.

There are other methods for routing also which are automatic but it will take time to explain. so just try this and check whether this works. There is some thing called MODGENS u can learn it from VIRTUOSO doc. it will make ur work a little simple.

Have a good time working with it. :-D