US6058496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-timed AC CIO wrap method and apparatus
Assignee: RPX Corp
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Filing: 1997-10-21
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Granted: 2000-05-02
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Expires: 2017-10-21
Abstract
Abstract A method and apparatus for testing a semiconductor chip includes providing the semiconductor chip with a common input/output (I/O) or bidirectional I/O pad. The I/O pad is electrically coupled to an off-chip driver (OCD) and an off-chip receiver (OCR). The OCD, I/O pad, and OCR are combined in a common input/output (CIO) or bidirectional I/O configuration. The I/O pad is effectively open circuited by an external tester and a performance parameter of the IO circuits connected to the open circuited pad is tested.
Inventors
- 👤 Pamela Sue Gillis
- 👤 Kevin William McCauley
- 👤 Ronald J. Prilik
- 👤 Donald Lawrence Wheater
- 👤 Francis Woytowich, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:16
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/317
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
70 words
A method of testing a semiconductor chip comprising the steps of: (a) providing the semiconductor chip with a common input/output configuration comprising an IO pad electrically coupled to an off-chip driver and to an off-chip receiver; and (b) performing a characterization test upon the common input/output configuration while leaving the off-chip driver and off-chip receiver disconnected from a load that is off the chip that can degrade accuracy of testing.
Claim 2
Independent Claim
70 words
A method of testing a semiconductor chip comprising the steps of: (a) providing the semiconductor chip with a common input/output configuration comprising an IO pad electrically coupled to an off-chip driver and to an off-chip receiver; and (b) performing a characterization test upon the common input/output configuration while leaving the off-chip driver and off-chip receiver disconnected from a load that is off the chip that can degrade accuracy of testing.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein the IO pad is not electrically contacted by a contractor of an external tester.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein the off-chip driver includes data and enable lines controlled by latches.
Claim 5
Dependent Claim
12 words
The method of claim 3, wherein the latches include boundary scan latches.
Claim 6
Dependent Claim
16 words
The method of claim 1, wherein the off-chip receiver includes an output connected to a latch.
Claim 7
Dependent Claim
13 words
The method of claim 5, wherein the latch includes a boundary scan latch.
Claim 8
Dependent Claim
27 words
The method of claim 1, further comprising the steps of: providing a first device for launching a transition; and providing a second device for capturing the transition.
Claim 9
Dependent Claim
25 words
The method of claim 7, wherein said performing step (c) comprises performing a differential time interval measurement for measuring a performance parameter of the chip.
Claim 10
Dependent Claim
12 words
The method of claim 7, wherein the first device includes a latch.
Claim 11
Dependent Claim
11 words
The method of claim 9, wherein the latch is clock controlled.
Claim 12
Dependent Claim
22 words
The method of claim 7, wherein the second device is a latch, the latch including a data input and a clock input.
Claim 13
Dependent Claim
15 words
The method of claim 11, wherein the second device further includes a boundary scan receiver.
Claim 14
Dependent Claim
31 words
The method of claim 1, further including the steps of: (a) providing at least two devices for sensing a transition; and (b) sensing the transition on the at least two devices.
Claim 15
Dependent Claim
13 words
The method of claim 13, wherein the at least two devices includes latches.
Claim 16
Dependent Claim
11 words
The method of claim 14, wherein the latches are clock controlled.
Claim 17
Dependent Claim
23 words
The method of claim 13, wherein at least two devices include latches, the latches each including a data input and a clock input.
Claim 18
Dependent Claim
16 words
The method of claim 16, wherein the at least two devices further include boundary scan receivers.
Claim 19
Dependent Claim
23 words
The method of claim 13, wherein the at least two devices are provided for sensing a transition at locations internal to the chip.
Claim 20
Dependent Claim
45 words
The method of claim 13, wherein one of the at least two devices is provided for sensing a transition at a location internal to the chip and the other of the at least two devices is provided for sensing a transition at the IO pad.
Claim 21
Independent Claim
73 words
A method of testing a semiconductor chip comprising the steps of: (a) providing the chip having a pad and I/O circuits connected to said pad, said I/O circuits comprising an off-chip driver and to an off-chip receiver; (b) testing a performance parameter of said I/O circuits connected to said pad while leaving the off-chip driver and off-chip receiver disconnected from a load that is off the chip that can degrade accuracy of testing.
Claim 22
Independent Claim
73 words
A method of testing a semiconductor chip comprising the steps of: (a) providing the chip having a pad and I/O circuits connected to said pad, said I/O circuits comprising an off-chip driver and to an off-chip receiver; (b) testing a performance parameter of said I/O circuits connected to said pad while leaving the off-chip driver and off-chip receiver disconnected from a load that is off the chip that can degrade accuracy of testing.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-02 | 2003-11-01 | 2004-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-02 | 2007-11-01 | 2008-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-02 | 2011-11-01 | 2012-05-02 | $7700.00 | Window Closed / Lapsed |