Digital variable-delay circuit having voltage-mixing interpolator and methods of testing input/output buffers using same

US6348826B1 · kind B1 · utility

Assignee

• Intel Corporation · US

Inventors

• Stephen R. Mooney · Beaverton, US
• Matthew B. Haycock · Beaverton, US
• Aaron Martin · Hillsboro, US
• Jonathan Spitz · Leonberg, DE
• Michael Sandhinti · Olympia, US

Key dates

• Filing date: Jun 28, 2000
• Grant date: Feb 19, 2002
• Expiry date: Jun 28, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03K2005/00065
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A variable-delay circuit on an integrated circuit is used to delay a periodic strobe signal. In normal operation, the strobe signal can be shifted 90 degrees to center it within a data bit cell. In test mode, it can also be shifted up to 270 degrees in N increments to measure the effective input latch setup and hold timings. The variable-delay circuit comprises a voltage-mixing interpolator circuit to produce phase delays in N increments. The variable-delay circuit can incorporate an existing delay locked loop. Also described are an electronic system, a data processing system, and various methods of performing on-chip testing and calibration.