Table Of Contents

Scan Patterns

Last Modified: November 23, 2020

Scan patterns are specialized patterns designed to test DUT circuitry using scan chains. Scan patterns contain scan pins and scan vectors in addition to DUT pins and vectors.

Typically scan patterns are generated as text or text pattern files (.digipatsrc) that can be imported into a Digital Pattern Editor project. You also can create scan patterns directly in the Digital Pattern Editor by creating a regular pattern and adding scan pins and scan vectors to that pattern.

To add a scan pin to your pattern, add the desired pin, select Change Pin Type from the context menu, and change the pin type to Scan Input or Scan Output. You can change a scan pin to a parallel pin (a regular DUT pin) by selecting Input/Output (default) from the context menu. The pattern grid view displays scan pins in the pin's column header.

Convert any vector to a scan vector by using the scan opcode. Specify the number of scan cycles in the scan vector using the single argument of the scan opcode. In the pattern grid view, a scan vector consists of a template item followed by the specified number of scan cycle items. Edit the pin state values of parallel pins in the template rows and the pin state values of scan pins in individual scan rows. Parallel pin state values are repeated in the scan rows, but you cannot edit parallel pin state values within scan rows.

You can insert, delete, copy, and paste scan rows like you would any other rows in the pattern grid view. Collapse or expand the scan rows in a scan vector using the button to the right of the scan opcode. You can expand or collapse all scan vectors in the pattern using the toolbar buttons in the pattern grid view and the pattern waveform view.

Treat scan patterns like regular patterns in the Digital Pattern Editor. You can burst scan patterns, view their waveforms, use the digital scope, and perform other expected tasks. During pattern execution, the scan cycles for a scan vector execute. The scan template scan row defines the behavior of the parallel pins on the scan cycles but does not execute. The behavior of the scan pins on the scan cycles is defined by the scan pin states.

Recently Viewed Topics