Patent · US Expired

Test shells for protecting proprietary information in asic cores

US5903578A · kind A · utility

15Cited by
7References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 8, 1996
Grant dateMay 11, 1999
Priority date
Expiry dateMar 8, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/318558
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A reduced netlist representing only partial netlist information for a logic block such as an ASIC embedded core is generated, such that proprietary information contained within the netlist can be kept confidential. The core is conceptually divided into a first section that can be completely tested using only a serial scan port, and a second section that can be tested in isolation from the first section using both primary inputs to the core as well as scan inputs. Netlist information for the first section is removed from the netlist, and the customer is supplied with serial scan test vectors that test the first section. Additionally, a multiplexing circuit selects either a serial scan chain for the entire logic block, or a scan chain that does not include scan cells within the first section of the logic bloc.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.