US 6,553,527 B1 · Programmable array built-in self test method and controller with programmable expect generator

Abstract

The present invention adds a programmable expect generator (PEG) that generates expected patterns of output for comparison to the actual outputs of an array while undergoing a complex test input sequence. The output of a programmable array built-in self test (PABIST) controller has its output increased to include separate control bits and a mask bit for a PEG. The PEG in one embodiment of the invention is substantially similar to a data control register that is programmed by a sequence of commands to generate the array input data patterns for testing an array. The program sequence that controls the PABIST and generates the input address, data and read/write patterns also outputs separate control bits to direct the PEG to generate expected outputs from the array when data from corresponding read addresses are read. The incorporation of a mask bit that accompanies each group of PEG control bits is used to inhibit the compare function that compares the output of the array to the output of the PEG. The mask bit controls when outputs of the array under test are compared to the PEG.

Claims19

Dependent claims

A programmable Array Built-In-Self-Test (ABIST) method for testing an array comprising the steps of:

scanning into a programmable ABIST controller a test instruction sequence;
executing said test instruction sequence;
outputting, in response to executing each instruction step in said test instruction sequence, first control bits and second control bits and coupling said first control bits to a programmable expect generator and coupling said second control bits to an array input address generator and an array input data generator for said array;
generating expect data outputs from said programmable expect generator in response to said first control bits concurrent with generating array input addresses from said array input address generator and array input data from said array input data generator in response to said second control bits;
generating array outputs in response to said array input addresses and said array input data;
comparing said expect data outputs, said array outputs, and selected control bits from said first control bits;
and
generating and outputting a sequence of pass/fail results in response to said comparison of said expect data outputs, said array outputs and said selected control bits.

5 more elements

Dependencies are inferred from the claim text.

Programmable array built-in self test method and controller with programmable expect generator

Life of this patent

Programmable array built-in self test method and controller with programmable expect generator

Life of this patent

Abstract

Claims19