what's the pll.save.io.std file for?

[egg]

what is the tdf file?

Hi all, when I use encounter to save the iofile, there are two files generated, one called pll.save.io, the other called pll.save.io.std, who can tell me what's the pll.save.io.std file for?

 

[cop02ia]

Re: what is the tdf file?

Hi,

Astro (Synopsys) uses a .tdf file to get the input arrangement of I/O cells.
I suppose there was a demand for conversion between the tools previously, although I think a LEF-DEF usage would seem more efficient.

But you know how this industry is, Synopsys acquires someone, Cadence acquires someone... and pretty soon, you have a bunch of different tools that need to pass data of different input formats around.

As for the users - well, we just pray that things don't get lost in translation.

 

[egg]

what is the tdf file?

Hi cop02ia

thanks for you reply!
BTW, could you tell me what's the different between LEF and DEF? I just know that the LEF file contains tech info and obs layer, pin/port layer, and something like that, but what's the DEF contain? Did a DEF file contain only layout info or both schematic info? and what's schematic info it has?
For our do soc flow, we didn't need DEF but LEF is a must? The DEF is only a option for exchange data or to speed up the design?

Anybody can answer me about the question above I should be very appreciate!

 

[cop02ia]

Re: what is the tdf file?

Hi,
I haven't looked at a DEF file in ages but as far as I can recall, it is like a LEF - only for layout.
What it has is physical co-ordinates for metal layers and that's as much as I remember (I'm not sure about cell location but I think that might be in the DEF file too).
The LEF file is used as input to setup the design, that's why it has technology information. The DEF has routing info. once the setup has been done.

"A Design Exchange Format (DEF) file contains the design-specific information of a circuit and
is a representation of the design at any point during the layout process."

The above quotation is from the Cadence LEF-DEF manual so I guess this should clear up things.They have some netlist info. to identify routing, maybe this is what you mean by schematic info?

 

[egg]

what is the tdf file?

Hi cop,

Thanks so much!