Knowledge Booster Training Bytes - What Is a Parameterized Cell and What Are the Advantages

In this Knowledge Booster blog, we talk about Parameterized Cells and explore how to design Pcells using the SKILL programming language and the Relative Object Design concept. We also introduce you to the videos and training materials that can help you understand and use this feature.

What is a Parameterized Cell?

A Parameterized Cell or Pcell is a programmable entity that creates customized instances. It improves productivity with complex layout designs. It eliminates errors and speeds up entering the layout data either manually or with the connectivity-driven tool flows available in the Virtuoso Layout Suite. Pcells also allow enhanced layout productivity in Virtuoso with Module Generators (Modgens)

See the Defining and listing the advantages of a Parameterized Cell training byte.

How Do You Create a Pcell?

For many of you working with Pcells involves using them from the PDK provided by the foundry or design team. However, creating a Pcell involves writing the SKILL procedure that identifies the library and cell, the input parameters to modify the generated cell, along with the code needed to create the device or layout structure. After the SKILL Pcell code is loaded, the cell is added to the specified Virtuoso library. See What is a Pcell SKILL program training byte.

The Pcell IDE is integrated with the SKILL IDE to assist in writing and debugging the code. See SKILL Development of Parameterized Cells online course.

A Parameterized Cell Example

Consider that you have created a transistor Pcell with a specified gate length, width, and gate shape. By changing the Pcell parameters, you can create a variety of transistors that have different gate lengths, widths, and number of gates. This looks like "One configurable cell for many instance variations in your designs". You got it!! That's what makes a Parameterized Cell special.

What is Relative Object Design (ROD)?

Going a step further, if ROD is combined with the SKILL Pcell program, it is easier to create objects and define their relationship at a high level of abstraction, like creating and aligning geometries. ROD functions provide enhanced capabilities to create both Pcells and hierarchical design blocks. See What is a ROD object and how to create a ROD object using SKILL?

What’s Next?

On the Cadence Learning and Support site (login required) you can:

• View the SKILL Pcells Training Byte Channel
• Take the free SKILL Development of Parameterized Cells online course
• And even earn a Digital Badge by passing an exam for the course.

If you need to develop and manage more complex Pcells check out Cadence PCell Designer.

Related Resources

Related Free Online Courses (support.cadence.com login required):

CDNLive OnDemand

• Cadence Virtuoso And Spectre Technology Update
• Introduction To An Automated PDK Verification Flow: "XveriFlow"
• Review and Customization of Virtuoso Parameterized Layout Generation

About Knowledge Booster Training Bytes

Knowledge Booster Training Bytes is an online journal that relays information about Cadence Training videos, online courses, and upcoming webinars that are available in the Learning section of the Cadence Learning and Support portal. This blog category brings you direct links to these videos, courses, and other related material, on a regular basis. 

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Vishnu Teja Salagrama

On behalf of the Cadence Training team