Controlling scan access to a scan chain

US8972808B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Benedikt Geukes · Stuttgart, DE
• Heiko Michel · Stuttgart, DE
• Matteo Michel · Chemnitz, DE
• Manfred Walz · Pfalzgrafenweiler, DE

Key dates

• Filing date: Mar 26, 2013
• Grant date: Mar 3, 2015
• Expiry date: Mar 26, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/318555
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A technique for controlling scan access of multiple scan devices (including or more slave scan devices and a master scan device) to a scan chain includes sending, by a requesting slave scan device included in the one or more slave scan devices, a first request for access to the scan chain to the master scan device. The master scan device and the one or more slave scan devices are connected to the scan chain. The technique also includes receiving, at the requesting slave scan device, an evaluation result from the master scan device and accessing, by the requesting slave scan device, the scan chain in response to the evaluation result indicating access granted. Finally, the technique includes sending, by the requesting slave scan device, one or more second requests for access to the scan chain to the master scan device in response to the evaluation result indicating access denied.