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US4852096A Expired / Lapsed US ⏱️ 0.0 years remaining

CN2 test pattern generator

Assignee: International Business Machines Corp
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Filing: 1987-08-14
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Granted: 1989-07-25
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Expires: 2007-08-14
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Abstract

Abstract A CN 2 memory testing circuit for generating a sequence of C(N 2 +1) memory addresses which will accomplish a CN 2 test with the least possible memory transitions. In one embodiment for an odd integer C, the mth bit in the memory address sequence comprises at least one repetition of a unique transition bit (UTB) pattern, where the UTB pattern comprises UTB Pattern=(C+1)/2 entries of 00, concatenated with C-1 entries of 10, concatenated with (C+1)/2 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1. The m+1th bit in this memory address sequence comprises m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of the different bit combinations aligned, at least once, with each different transition in the UTB pattern. A second embodiment, with an even integer C, is similar to the first embodiment, but with a UTB pattern comprising UTB pattern=C(2) 2m-1 entries of 00, concatenated with C(2) 2m-1 entries of 01, concatenated with C(2) 2m-1 entries of 10, concatenated with C(2) 2m-1 entries of 11.

Inventors

  • 👤 Robert P. Brinkman

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 21:59
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/04; G11C29/08; G11C29/10; G11C29/12; G11C29/18; G11C29/20; G11C29/56

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 111 words
A CN 2 memory testing circuit comprising: counter means with at least M register stages, stepped at a frequency F in /C, for generating M bit patterns in said M register stages, of N 2 +1 bits each, where C is the multi-cycle coefficient and is an integer; means for concurrently sampling each of said M bit patterns at a sampling frequency of F in ; means for combining said bit patterns to form N 2 +1 consecutive memory addresses of M bits each to perform complete CN 2 memory testing; and means for applying said consecutive memory addresses to the address inputs of a memory to facilitate CN 2 testing.
Claim 2
Dependent Claim 111 words
A CN 2 memory testing circuit comprising: counter means with at least M register stages, stepped at a frequency F in /C, for generating M bit patterns in said M register stages, of N 2 +1 bits each, where C is the multi-cycle coefficient and is an integer; means for concurrently sampling each of said M bit patterns at a sampling frequency of F in ; means for combining said bit patterns to form N 2 +1 consecutive memory addresses of M bits each to perform complete CN 2 memory testing; and means for applying said consecutive memory addresses to the address inputs of a memory to facilitate CN 2 testing.
Claim 3
Dependent Claim 94 words
A CN 2 testing apparatus as defined in claim 1, wherein said counter means includes 2M register stages; and wherein said sampling means includes means for selectively sampling said register stages to obtain one bit pattern comprising alternate bit combinations of 00 and 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, and to obtain a second bit pattern comprising the different bit combinations 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned at least once, with each different transition in said first bit pattern.
Claim 4
Dependent Claim 135 words
A CN 2 testing apparatus as defined in claim 1, wherein said counter means includes at least 2M register stages; and wherein said sampling means includes means for selectively sampling said 2M register stages to obtain an mth bit pattern or its complement, comprising at least one repetition of a unique transition bit (UTB) pattern, and to obtain an m+1th bit pattern, wherein said UTB pattern comprises UTB pattern=(C+1)/2 entries of 00, concatenated with C-1 entries of 10, concatenated with (C+1)/2 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where C is an odd integer, m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, at least once, with each different transition in said UTB pattern.
Claim 5
Dependent Claim 153 words
A CN 2 testing apparatus as defined in claim 1, wherein said counter means includes at least 2M register stages; and wherein said sampling means includes means for selectively sampling said register stages to obtain an mth bit pattern or its complement comprising at least one repetition of a unique transition bit (UTB) pattern, and to obtain an m+1th bit, wherein said UTB pattern comprises UTB pattern=C(2) 2m-1 entries of 00, concatenated with C(2) 2m-1 entries of 01, concatenated with C(2) 2m-1 entries of 10, concatenated with C(2) 2m-1 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where m=0, 1, . . . M-1, and C is the multi-cycle coefficient and is an even integer; and m+1th bit pattern=a plurality of the different bit combinations 00, 01, 10, and 11, in any order, with each of said different bit combinations aligned with each different transition in said UTB pattern.
Claim 6
Dependent Claim 142 words
An N 2 memory testing apparatus, comprising: means for generating a first bit pattern comprising alternate bit combinations of 00 and 11, beginning at any point in the pattern, to yield the transitions 0-0, 0-1, 1-0, and 1-1; means for generating a second bit pattern comprising the different bit combinations 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned in time at least once, with each different transition in said first bit pattern, means for forming N 2 consecutive binary memory addresses of M bits each, with said first bit pattern comprising an arbitrary mth significance bit in said N 2 consecutive addresses, and with said m+1th bit pattern comprising an arbitrary m+1th significance bit in said N 2 consecutive addresses; and means for applying said generated series of memory addresses to a memory.
Claim 7
Dependent Claim 142 words
An N 2 memory testing apparatus, comprising: means for generating a first bit pattern comprising alternate bit combinations of 00 and 11, beginning at any point in the pattern, to yield the transitions 0-0, 0-1, 1-0, and 1-1; means for generating a second bit pattern comprising the different bit combinations 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned in time at least once, with each different transition in said first bit pattern, means for forming N 2 consecutive binary memory addresses of M bits each, with said first bit pattern comprising an arbitrary mth significance bit in said N 2 consecutive addresses, and with said m+1th bit pattern comprising an arbitrary m+1th significance bit in said N 2 consecutive addresses; and means for applying said generated series of memory addresses to a memory.
Claim 8
Dependent Claim 57 words
An apparatus as defined in claim 5, wherein said first and second bit generating means comprise counting means including a series of register stages stepped at a frequency F in , with one of said register stages generating said first bit pattern, and with one or more other of said register stages generating said second bit pattern.
Claim 9
Dependent Claim 26 words
An apparatus as defined in claim 6, wherein said address forming means comprises means for sampling said register stages to generate said M bit memory addresses.
Claim 10
Dependent Claim 68 words
An apparatus as defined in claim 7, wherein said memory address generating means comprises: counter means with a series of register stages 0 to 2M, stepped at a frequency F in , means for sampling at said frequency F in the register stage 1 to obtain said first bit pattern, and for sampling at said frequency F in the register stage 3 to obtain said second bit pattern.
Claim 11
Dependent Claim 195 words
A CN 2 memory testing apparatus, comprising: means for generating CN 2 consecutive binary memory addresses, with each memory address having M bits, with the consecutive listing of the same one of those bits in each consecutive generated address yielding an mth bit pattern or its complement, with said mth bit pattern comprising at least one repetition of a unique transition bit (UTB) pattern, wherein the UTB pattern comprises UTB pattern=(C+1)/2 entries of 00, concatenated with C-1 entries of 10, concatenated with (C+1)/2 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where C is the multi-cycle coefficient and is an odd integer, and with the consecutive listing of the m+1th bit in each consecutive generated memory address yielding an m+1th bit pattern or its complement, wherein the m+1th bit pattern comprises m+1th Bit Pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, at least once, with each different transition in said UTB pattern, where m=0, 1, . . . M-1; and means for applying said generated series of memory addresses to the address inputs of a memory.
Claim 12
Dependent Claim 195 words
A CN 2 memory testing apparatus, comprising: means for generating CN 2 consecutive binary memory addresses, with each memory address having M bits, with the consecutive listing of the same one of those bits in each consecutive generated address yielding an mth bit pattern or its complement, with said mth bit pattern comprising at least one repetition of a unique transition bit (UTB) pattern, wherein the UTB pattern comprises UTB pattern=(C+1)/2 entries of 00, concatenated with C-1 entries of 10, concatenated with (C+1)/2 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where C is the multi-cycle coefficient and is an odd integer, and with the consecutive listing of the m+1th bit in each consecutive generated memory address yielding an m+1th bit pattern or its complement, wherein the m+1th bit pattern comprises m+1th Bit Pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, at least once, with each different transition in said UTB pattern, where m=0, 1, . . . M-1; and means for applying said generated series of memory addresses to the address inputs of a memory.
Claim 13
Dependent Claim 79 words
A CN 2 memory testing apparatus as defined in claim 9, wherein said memory address generating means comprises counter means with a series of register stages 0 to 2M, stepped at a frequency F in /C; means for obtaining an m=0 bit pattern from the register stage one, and for obtaining a plurality of different second bit patterns from different respective odd register stages; and means for combining said bit patterns to form memory addresses of M bits each.
Claim 14
Dependent Claim 200 words
A CN 2 memory testing apparatus, comprising: means for generating CN 2 consecutive binary memory addresses, with each memory address having M bits, with the consecutive listing of the mth bit in each memory address of M bits yielding an mth bit pattern or its complement, comprising at least one repetition of a unique transition bit (UTB) pattern, wherein said UTB pattern comprises UTB pattern=C(2) 2m-1 entries of 00, concatenated with C(2) 2m-1 ) entries of 01, concatenated with C(2) 2m-1 entries of 10, concatenated with C(2) 2m-1 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where m=0, 1, . . . M-1, and C is the multi-cycle coefficient and is an even integer, and with the consecutive listing of the m+1th bit in each consecutive generated memory address yielding an m+1th bit pattern or its complement, wherein the m+1th bit pattern comprises m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, at least once, with each different transition in said UTB pattern; and means for applying said generated series of memory addresses to the address inputs of a memory.
Claim 15
Dependent Claim 200 words
A CN 2 memory testing apparatus, comprising: means for generating CN 2 consecutive binary memory addresses, with each memory address having M bits, with the consecutive listing of the mth bit in each memory address of M bits yielding an mth bit pattern or its complement, comprising at least one repetition of a unique transition bit (UTB) pattern, wherein said UTB pattern comprises UTB pattern=C(2) 2m-1 entries of 00, concatenated with C(2) 2m-1 ) entries of 01, concatenated with C(2) 2m-1 entries of 10, concatenated with C(2) 2m-1 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where m=0, 1, . . . M-1, and C is the multi-cycle coefficient and is an even integer, and with the consecutive listing of the m+1th bit in each consecutive generated memory address yielding an m+1th bit pattern or its complement, wherein the m+1th bit pattern comprises m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, at least once, with each different transition in said UTB pattern; and means for applying said generated series of memory addresses to the address inputs of a memory.
Claim 16
Dependent Claim 90 words
A CN 2 memory testing apparatus as defined in claim 11, wherein said memory address generating means comprises counter means with a series of register stages 0 to 2M, stepped at a frequency, F in /C; and means for generating each bit pattern by alternately sampling the value in one of an even or an adjacent odd register stage, and then sampling the value in the other of the even or the odd register stage; and means for combining said bit patterns to form memory addresses of M bits each.
Claim 17
Independent Claim 142 words
A method for generating addresses to facilitate N 2 memory testing, comprising generating an mth bit pattern comprising alternate bit combinations of 00 and 11, beginning at any point in the pattern, to yield the transitions 0-0, 0-1, 1-0, and 1-1; generating an m+1th bit pattern comprising a plurality of different bit combinations 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned at least once, with each different transition in said mth bit pattern, forming N 2 consecutive binary memory addresses of M bits each, with said mth bit pattern comprising an arbitrary significance bit in said N 2 consecutive addresses, and with said m+1th bit pattern comprising the next higher significance bit from said mth bit in said N 2 consecutive addresses; and applying said generated series of memory addresses to a memory.
Claim 18
Independent Claim 142 words
A method for generating addresses to facilitate N 2 memory testing, comprising generating an mth bit pattern comprising alternate bit combinations of 00 and 11, beginning at any point in the pattern, to yield the transitions 0-0, 0-1, 1-0, and 1-1; generating an m+1th bit pattern comprising a plurality of different bit combinations 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned at least once, with each different transition in said mth bit pattern, forming N 2 consecutive binary memory addresses of M bits each, with said mth bit pattern comprising an arbitrary significance bit in said N 2 consecutive addresses, and with said m+1th bit pattern comprising the next higher significance bit from said mth bit in said N 2 consecutive addresses; and applying said generated series of memory addresses to a memory.
Claim 19
Dependent Claim 36 words
A method as defined in claim 13, wherein said mth and m+1th bit pattern generating steps comprise: stepping a multi-stage counter; and sampling different stages in said counter to obtain said first and second bit patterns.
Claim 20
Dependent Claim 64 words
A method as defined in claim 14, wherein for a counter with stages 0 to 2M stepped at a frequency F in , said sampling step includes the step of sampling at said frequency F in the register stage 1 to obtain said mth bit pattern, and for sampling at said frequency F in the register stage 3 to obtain said m+1th bit pattern.
Claim 21
Independent Claim 151 words
A method for generating addresses to facilitate CN 2 memory testing, where C is the multi-cycle coefficient and is an odd integer, comprising the steps of: generating M bit patterns, with an mth bit pattern or its complement comprising at least one repetition of a unique transition bit (UTB) pattern, wherein said UTB pattern comprises UTB pattern=(C+1)/2 entries of 00, concatenated with C-1 entries of 10, concatenated with (C+1)/2 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, and with an m+1th bit pattern comprising m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned with each different transition in said UTB pattern; combining said M bit patterns to form CN 2 consecutive binary memory addresses, of M bits each; and applying said consecutive memory addresses to the address inputs of a memory.
Claim 22
Independent Claim 151 words
A method for generating addresses to facilitate CN 2 memory testing, where C is the multi-cycle coefficient and is an odd integer, comprising the steps of: generating M bit patterns, with an mth bit pattern or its complement comprising at least one repetition of a unique transition bit (UTB) pattern, wherein said UTB pattern comprises UTB pattern=(C+1)/2 entries of 00, concatenated with C-1 entries of 10, concatenated with (C+1)/2 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, and with an m+1th bit pattern comprising m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned with each different transition in said UTB pattern; combining said M bit patterns to form CN 2 consecutive binary memory addresses, of M bits each; and applying said consecutive memory addresses to the address inputs of a memory.
Claim 23
Dependent Claim 44 words
A method as defined in claim 16, wherein said bit pattern generating step comprises the step of concurrently sampling odd register stages in at least a 2M stage counter stepped at a frequency F in , with a sampling frequency of F in /C.
Claim 24
Independent Claim 167 words
A method for generating addresses to facilitate CN 2 memory testing, where C is the multi-cycle coefficient and is an even integer, comprising the steps of: generating M bit patterns, with the mth bit pattern or its complement comprising at least one repetition of a unique transition bit (UTB) pattern, where the UTB pattern comprises UTB Pattern=C(2) 2m-1 entries of 00, concatenated with C(2) 2m-1 entries of 01, concatenated with C(2) 2m-1 entries of 10, concatenated with C(2) 2m-1 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where m=0, 1, . . . M-1, and; with the m+1th bit comprising m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, with each different transition in said UTB pattern; combining said M bit patterns to form CN 2 consecutive binary memory addresses, of M bits each; and applying said consecutive memory addresses to the address inputs of a memory.
Claim 25
Independent Claim 167 words
A method for generating addresses to facilitate CN 2 memory testing, where C is the multi-cycle coefficient and is an even integer, comprising the steps of: generating M bit patterns, with the mth bit pattern or its complement comprising at least one repetition of a unique transition bit (UTB) pattern, where the UTB pattern comprises UTB Pattern=C(2) 2m-1 entries of 00, concatenated with C(2) 2m-1 entries of 01, concatenated with C(2) 2m-1 entries of 10, concatenated with C(2) 2m-1 entries of 11, to yield the transitions 0-0, 0-1, 1-0, and 1-1, where m=0, 1, . . . M-1, and; with the m+1th bit comprising m+1th bit pattern=a plurality of different combinations of 00, 01, 10, and 11, in any order, but with each of said different bit combinations aligned, with each different transition in said UTB pattern; combining said M bit patterns to form CN 2 consecutive binary memory addresses, of M bits each; and applying said consecutive memory addresses to the address inputs of a memory.
Claim 26
Dependent Claim 69 words
A CN 2 memory testing apparatus as defined in claim 18, wherein said bit pattern generating step comprises the step of: generating said mth bit pattern by alternately sampling the value in an even register stage of a 2M stage counter stepped at a frequency F in /C, and then sampling the value in the next higher numbered-odd register stage thereof, with the sampling frequency being F in /C.

References Cited (Backward Citations)

US4263669A Cited
US4429389A Cited
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