what kind of CAD sw do you use?

[JOEL_HWANG]

Hi all!!
Today signed up here.
I use ORCAD and PADS and start to learn Expedtion pcb recently.
I wonder what kind of cad mostly used.
Could you leave you comment?
Have a nice day.
Joel

 

[kabaleevisu]

HI
I am using cadence allegro 16.2 it is most useful cad tool

 

[moataz fouad]

Hi,
I use OrCAD Layout & PCB Editor (Allegro).

 

[kabaleevisu]

hi every one

any body now how to length matching is matched in perticular net ??

 

[cks3976]

Length matching can be done by defining a pair of traces as differential in Orcad capture (version 16.x). This will automatically create a net class as differential and add these traces to that net class. And length matching will be taken care by the Tool (Allegro/Pads etc). Alternately you can create a differential net class in layout tool also.

Hope that helps

 

[karthiksmartone]

why we take clock as a ref in length matching?

 

[anilrock87]

Hi,
I use ALTIUM

 

[SHABU]

Hi ,

I use Allegro & Altium

 

[SHABU]

Hi karthiksmartone,

The data group operates at twice the clock speed and its signal integrity is of higher concern. In addition, the data group constitutes the largest
portion of the memory bus and consists of the majority of the trace matching requirements, those of the data lanes.
The address/command, control, and the data groups all have a relationship to the routed clock. Therefore, clock is taken as a reference for length matching ddr signals.

 

[kabaleevisu]

can you explain about DDR placement ??

 

[SHABU]

Hi ,

DDR placement generally depends on the DDR device we use. It is mainly based on the timing requirement.
Mostly we used to place them in a manner that we get those routes as close as possible.

SHABU