International Business Machines Corporation

Matthew B Schallhorn

Steven Michael Douskey

Mary Prilotski Kusko

Michael John Hamilton

Amanda Renee Kaufer

A method and circuit are provided for implementing enhanced scan data testing with minimization of over masking in an on product multiple input signature register (OPMISR) test due to Channel Mask Enable (CME) sharing, and a design structure on which the subject circuit resides. A common Channel Mask Scan Registers (CMSR) logic is used with a multiple input signature register (MISR). Individual local addressing is used for implementing enhanced scan data testing. An architecture and algorithm efficiently expand and target the use of the CME pins to minimize over-masking, to increase test pattern effectiveness with the use of individual local addressing.

Minimization of over-masking in an on product multiple input signature register (OPMISR)

A method and test circuit are provided for implementing enhanced scan data testing with minimization of over masking in an on product multiple input signature register (OPMISR) test, and a design structure on which the subject circuit resides. Common Channel Mask Scan Registers (CMSR) data is used with a multiple input signature register (MISR) in each satellite. A test algorithm control is used for implementing enhanced scan data testing by independently skewing scan unload shifting of selected OPMISR+ satellite by selected cycles. With this modified shifting, for the same test or a repeated run of the test, Channel Mask Enable (CME) triggered masking lines up on a different bit position in channels of each satellite avoiding over masking.

A method and test circuit are provided for implementing enhanced scan data testing with removal of over masking in an on product multiple input signature register (OPMISR) test, and a design structure on which the subject circuit resides. Common Channel Mask Scan Registers (CMSR) data is used with a multiple input signature register (MISR) in each satellite. A test algorithm control is used for implementing enhanced scan data testing to allow sharing the CMSR data and common Channel Mask Enable (CME) pins with removal of over masking. Selectively pausing scan unload is provided for each respective satellite when wrong CME data for the respective satellite is at the CME pins. Each satellite includes a select signal which controls advancing the scan into the MISR. The select signal is used to selectively pause the scan unload for the respective satellite.

Removal of over-masking in an on product multiple input signature register (OPMISR) test

A method and circuit are provided for implementing enhanced scan data testing with over masking removal in an on product multiple input signature register plus (OPMISR+) test due to common Channel Mask Scan Registers (CMSRs) loading, and a design structure on which the subject circuit resides. An OPMISR plus satellite includes a multiple input signature register (MISR) for data collection and a plurality of associated scan channels. A common Channel Mask Scan Registers (CMSR) logic is used with the multiple input signature register (MISR). Unique CMSR data is loaded into at least one OPMISR plus satellite for implementing enhanced scan data testing. Scan pausing is used to reduce the amount of CMSR scan load data by loading the unique CMSR data only when needed.

Implementing over-masking removal in an on product multiple input signature register (OPMISR) test due to common channel mask scan registers (CMSR) loading

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Greensboro, NC, United States of America

Matthew B Schallhorn