Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Algorithmic Random Pattern Generator

IP.com Disclosure Number: IPCOM000035976D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 79K

Publishing Venue

IBM

Related People

Mirek, GA: AUTHOR [+2]

Abstract

Disclosed is an implementation of an Algorithmic Random Pattern Generator (ARPG), which uses deterministic patterns as seeds and generates random patterns.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 3

Algorithmic Random Pattern Generator

Disclosed is an implementation of an Algorithmic Random Pattern Generator (ARPG), which uses deterministic patterns as seeds and generates random patterns.

Fig. 1 shows a test system which includes the ARPG. It is generally conceived to become part of the VLSI tester itself, although it could possibly be integrated as part of the device under test (DUT).

Data from the tester is loaded into the ARPG. The ARPG generates (4n-2) new patterns, where 'n' is the number of bits in the seed. Each new pattern is applied to the DUT, and the result of those patterns will be stored in a Multiple Input Signature Register (MISR) (not shown). After all of the ARPG's patterns have been applied, the results are measured by the tester. A reduction in tester data storage requirements has been achieved due to the ARPG's pattern generation process (stimulus patterns) and the MISR's measurement process (measurement patterns).

Fig. 2 shows an n-bit state machine for the ARPG. The ARPG's task is to generate new patterns. However, it needs a starting point. This starting point is referred to as a 'seed' and is an actual test pattern in itself. The seed can be generated by currently existing software. The seed(s) will exist in the tester's main 'pattern memory' and will be loaded into the ARPG's n-bit SRL through the "SCAN IN" input. This is very similar to how the DUT's SRLs are loaded if no A4RPG exists in the test setup. Once the ARPG's SRL is loaded, the random pattern generation may proceed.

Random patterns may be generated using the seed as the initial pattern. In this particular version of the ARPG, it has been decided that t...