Implementing enhanced pseudo random pattern generators with hierarchical linear feedback shift registers (LFSRs)

摘要

A method and circuit for implementing enhanced Logic Built In Self Test (LBIST) diagnostics, and a design structure on which the subject circuit resides are provided. A plurality of pseudo random pattern generators (PRPGs) is provided, each PRPG comprising one or more linear feedback shift registers (LFSRs). Each respective PRPG includes an XOR feedback input selectively receiving a feedback from another PRPG and predefined inputs of the respective PRPG. A respective XOR spreading function is coupled to a plurality of outputs of each PRPG with predefined XOR spreading functions applying test pseudo random pattern inputs to LBIST channels for LBIST diagnostics.

主权项

1. A method for implementing enhanced Logic Built In Self Test (LBIST) diagnostics comprising:
providing a plurality of pseudo random pattern generators (PRPGs), each PRPG comprising one or more linear feedback shift registers (LFSRs); providing each respective PRPG with an Exclusive-Or (XOR) feedback input for selectively receiving a feedback coupled from another PRPG and predefined inputs of the respective PRPG; providing a respective XOR spreading function coupled to a plurality of outputs of each PRPG; and applying test pseudo random pattern inputs to LBIST channels for LBIST diagnostics with predefined XOR spreading functions; and providing a plurality of child Multiple Input Signature Registers (MISRs) collecting and compressing LBIST channel data.