Browse Prior Art Database

Memory Testing Using Prime Number Sequence Background Pattern

IP.com Disclosure Number: IPCOM000105608D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Franch, RL: AUTHOR [+5]

Abstract

Disclosed is a test procedure using prime number sequences that provides a single pass test for stuck or shorted address pins and decoder defects.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Memory Testing Using Prime Number Sequence Background Pattern

      Disclosed is a test procedure using prime number sequences that
provides a single pass test for stuck or shorted address pins and
decoder defects.

      A sequential memory system that stores sequential trace data
from a computer system requires a testing procedure that will
identify addressing errors and delta 'I' noise problems.  An
addressing problem will occur if any address line is held high, low,
or shorted to another signal line.  Writing background patterns that
are cyclic on binary addresses will not test for addressing problems.
Also, there was a need to develop background patterns that would also
test for delta 'I' problems at the same time.

      The conventional method of address testing [*] is not possible
with the organization of this sequential memory system.  Only two
memory operations are possible with this memory:  1) write all cells
sequentially or 2) read all cells sequentially.  The conventional
method is to write a background test pattern to memory and then read
out each cell incrementally, verify that it is correct, write back
the complement of the cell just read, and then read the complement.
This is repeated for the next cell until all locations have been
tested.

      The disclosed solution to this problem was to write a
background pattern that contained a prime number of data elements.
When this pattern is read out of the memory it will reveal many
addressing problems.  Addressing to memories is cyclic on binary
addresses.  If a prime number sequence is written into the memory,
the sequence will never be cyclic on any binary address bit.

      The following is an example of a prime number background
pattern of length 7 for a 32 b...