Basics of PDK

A PDK is a "Process Design Kit" - it's a set of libraries and associated data (model files, physical verification rule files, control files for various tools) to allow you to design in a particular technology.

A flow is far more generic than that - it could mean many things. Generally it means the preferred way of navigating  through a particular task.

Regards,

Andrew.

Ok. But could you be more specific in terms of how it is related to the actual fabrication process. You have mentioned "design in a particular technology" so I'm guessing gpdk180 is a PDK.

Again please don't mind the primitive question, google doesn't help much with such stuff :)

Thanks and Regards.

gpdk180 (together with gpdk090 and gpdk045) are slightly unusual examples in that they are "Generic PDKs" which are not tied to a real process. They essentially allow you to design using a "generic" 0.18u, 90nm or 45nm process which isn't real - the benefit of this is that the designs then don't reveal proprietary foundry information. So that's a good teaching aid, and allows Cadence to produce examples, demonstrations and so on that don't require an NDA with a foundry (which would complicate matters enormously).

The PDK is a set of data which allows you to enter a design. So, it will contain device-level components (transistors, resistors, capacitors etc) which you can place on a schematic, and will have the associated views to allow you to simulate them (e.g. in spectre, AMS Designer), lay them out (so will have PCells (Parameterised Cells) which generate the layout for a variety of different device dimensions), and support for a number of other tools, such as Physical Verification (Assura or PVS) DRC and LVS,  Parasitic Extraction (QRC) and so on. Other PDKs will have support for other tools.

Essentially, with a PDK you can enter a design, schematic and layout, in a form that would allow you to send the layout to the foundry for manufacture. Obviously you can't do that with GPDK PDKs because they're an artificial example.

As I said before, a flow is simply a documented way of navigating your way through a set of tools to complete a task. A PDK doesn't necessarily dictate a flow, but many foundries have what they call a "Reference Flow" which describes how they expect you to use their technology data to complete a task.

I cannot answer your question about "IQA frameworks for Quality Assurance". That's something  you would need to ask a specific supplier of a PDK for, as I doubt there is a single framework that is used as standard (I'm certainly not aware of one). A bit of an odd question, to be honest.

Regards,

Andrew.

Ok,I understand what you mean now. Thanks a ton and yeah, I was just trying my luck with the "IQA Framework" question.

Thanks and Regards