Compressed scan chain diagnosis by internal chain observation, processes, circuits, devices and systems

US11592483B2 · kind B2 · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Prakash Narayanan · Bengaluru, IN
• Rubin Ajit Parekhji · Bengaluru, IN
• Arvind Jain · Sunnyvale, US
• Sundarrajan Subramanian · Savanuru, IN

Key dates

• Filing date: Aug 6, 2021
• Grant date: Feb 28, 2023
• Expiry date: Aug 6, 2041

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/318547
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Electronic scan circuitry includes a decompressor (510), a plurality of scan chains (520.i) fed by the decompressor (510), a scan circuit (502, 504) coupled to the plurality of scan chains (520.i) to scan them in and out, a masking circuit (590) fed by the scan chains (520.i), and a scannable masking qualification circuit (550, 560, 580) coupled to the masking circuit (590), the masking qualification circuit (550, 560, 580) scannable by scan-in of bits by the decompressor (510) along with scan-in of the scan chains (520.i), and the scannable masking qualification circuit (550, 560, 580) operable to hold such scanned-in bits upon scan-out of the scan chains through the masking circuit (590). Other scan circuitry, processes, circuits, devices and systems are also disclosed.