US5115191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Testing integrated circuit capable of easily performing parametric test on high pin count semiconductor device
Assignee: Toshiba Corp
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Filing: 1991-06-11
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Granted: 1992-05-19
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Expires: 2011-06-11
Abstract
Abstract A boundary-scan-testing integrated circuit adapted to both a functional test of an entire IC chip and a parametric test for input and output buffers, connected to pads of the IC chip, in a periphery cell area of the IC chip. First memory circuits are respectively formed in an input buffer portion, an output buffer portion, and a bidirectional buffer portion, which are provided in the peripheral cell area of the IC chip. Second memory devices control ON/OFF operations of active elements, formed in the input buffer portion and the bidirectional buffer portion, for supplying a pad potential. Third memory devices control ON/OFF operations of tristate buffers of the output buffer portion and the bidirectional buffer portion. The first, second, and third memory devices are serially connected, thereby constituting a shift register controlled by a first control signal. First and second data selectors are operated by data output from the shift register, thereby controlling input and output buffers, and resistors for determining a potential of pads.
Inventors
- 👤 Takashi Yoshimori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:24
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/31712; G01R31/31715; G01R31/3181; G01R31/3185; G01R31/318533; G01R31/318572; G11; G11C; G11C7/00; G11C7/10; G11C7/1048
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
244 words
A boundary-scan-testing integrated circuit adapted to both a functional test on an entire IC chip and a parametric test, comprising: first memory circuits respectively formed in an input buffer portion, an output buffer portion, and an bidirectional buffer portion, which are provided in a peripheral cell area of the IC chip and respectively connected to an input pad, an output pad, and an bidirectional pad; second memory circuits, formed in the peripheral cell area of the IC chip, for controlling ON/OFF operations of active elements, formed in the input buffer portion and the bidirectional buffer portion, for supplying a pad potential; third memory circuits, formed in the peripheral cell area of the IC chip, for controlling ON/OFF operations of tristate buffers of the output buffer portion and the bidirectional buffer portion; circuit means functioning as a shift register controlled by a first control signal, said circuit means being constituted by said first, second, and third memory circuits serially connected; first data selectors for receiving data output from the first memory circuits and a signal output from the input buffer, selecting one of them in accordance with a second control signal, and supplying it to an internal logic circuit of the IC chip; and second data selectors for receiving data output from the third memory circuits and a normal operation signal, selecting one of them in accordance with a third control signal, and supplying it as an operation control signal to the output buffer portion.
Claim 2
Dependent Claim
244 words
A boundary-scan-testing integrated circuit adapted to both a functional test on an entire IC chip and a parametric test, comprising: first memory circuits respectively formed in an input buffer portion, an output buffer portion, and an bidirectional buffer portion, which are provided in a peripheral cell area of the IC chip and respectively connected to an input pad, an output pad, and an bidirectional pad; second memory circuits, formed in the peripheral cell area of the IC chip, for controlling ON/OFF operations of active elements, formed in the input buffer portion and the bidirectional buffer portion, for supplying a pad potential; third memory circuits, formed in the peripheral cell area of the IC chip, for controlling ON/OFF operations of tristate buffers of the output buffer portion and the bidirectional buffer portion; circuit means functioning as a shift register controlled by a first control signal, said circuit means being constituted by said first, second, and third memory circuits serially connected; first data selectors for receiving data output from the first memory circuits and a signal output from the input buffer, selecting one of them in accordance with a second control signal, and supplying it to an internal logic circuit of the IC chip; and second data selectors for receiving data output from the third memory circuits and a normal operation signal, selecting one of them in accordance with a third control signal, and supplying it as an operation control signal to the output buffer portion.
Claim 3
Dependent Claim
22 words
A boundary-scan-testing integrated circuit according to claim 1, wherein said first, second, and third memory circuits are flip-flops of the same type.
Claim 4
Dependent Claim
34 words
A boundary-scan-testing integrated circuit according to claim 1, wherein said active elements are constituted by MOS FETs, and data output from said second memory devices is applied to the gates of the MOS FETs.
Claim 5
Dependent Claim
16 words
A boundary-scan-testing integrated circuit according to claim 3, wherein said MOS FETs function as pull-up resistors.
Claim 6
Dependent Claim
16 words
A boundary-scan-testing integrated circuit according to claim 3, wherein said MOS FETs function as pull-down resistors.
Claim 7
Dependent Claim
22 words
A boundary-scan-testing integrated circuit according to claim 1, wherein said first and second data selectors are each constituted by a two-input multiplexer.
Claim 8
Dependent Claim
52 words
A boundary-scan-testing integrated circuit according to claim 1, wherein the normal operation signal received by said second data selectors has a constant potential for enabling an operation of the output buffer which receives the operation control signal from said second data selectors, if the output buffer is connected to the output pad.
Claim 9
Dependent Claim
48 words
A boundary-scan-testing integrated circuit according to claim 1, wherein the normal operation signal received by said second data selectors is an enable control signal supplied from the integral logic circuit and enabling ON/OFF operations of the output buffer, if the output buffer is connected to the bidirectional pad.
Claim 10
Dependent Claim
30 words
A boundary-scan-testing integrated circuit according to claim 1, further comprising common connection means for directly connecting the pads which should be subjected to a parametric test on the IC chip.
Claim 11
Dependent Claim
32 words
A boundary-scan-testing integrated circuit according to claim 9, wherein said common connection means is formed on an IC chip pattern on a wafer from which IC chips are not to be dice.
Claim 12
Dependent Claim
249 words
A boundary-scan-testing integrated circuit adapted to both a functional test on an entire IC chip and a parametric test on each of input buffers and output buffers provided in a peripheral cell area connected to pads of the IC chip, comprising: first memory devices respectively provided for a signal input line connected to the input buffer and a signal output line connected to the output buffer in the peripheral cell area of the IC chip; active elements, provided in the peripheral cell area of the IC chip, for applying a potential to a connection node of the input buffer and a pad; second memory circuits for controlling ON/OFF operation of the active elements; third memory circuits, provided in the peripheral cell area of the IC chip, for controlling ON/OFF operations of the signal output line; circuit means functioning as a shift register controlled by a first control signal, said circuit means being constituted by said first, second, and third memory circuits serially connected; first data selectors for receiving data output from the first memory circuits and a signal output from the signal input line, selecting one of them in accordance with a second control signal, and supplying it to an internal logic circuit of the IC chip; and second data selectors for receiving data output from the third memory circuits and a normal operation signal, selecting one of them in accordance with a third control signal, and supplying it as an operation control signal to the output buffer portion.
Claim 13
Dependent Claim
249 words
A boundary-scan-testing integrated circuit adapted to both a functional test on an entire IC chip and a parametric test on each of input buffers and output buffers provided in a peripheral cell area connected to pads of the IC chip, comprising: first memory devices respectively provided for a signal input line connected to the input buffer and a signal output line connected to the output buffer in the peripheral cell area of the IC chip; active elements, provided in the peripheral cell area of the IC chip, for applying a potential to a connection node of the input buffer and a pad; second memory circuits for controlling ON/OFF operation of the active elements; third memory circuits, provided in the peripheral cell area of the IC chip, for controlling ON/OFF operations of the signal output line; circuit means functioning as a shift register controlled by a first control signal, said circuit means being constituted by said first, second, and third memory circuits serially connected; first data selectors for receiving data output from the first memory circuits and a signal output from the signal input line, selecting one of them in accordance with a second control signal, and supplying it to an internal logic circuit of the IC chip; and second data selectors for receiving data output from the third memory circuits and a normal operation signal, selecting one of them in accordance with a third control signal, and supplying it as an operation control signal to the output buffer portion.
Claim 14
Dependent Claim
22 words
A boundary-scan-testing integrated circuit according to claim 11, wherein said first, second, and third memory circuits are flip-flops of the same type.
Claim 15
Dependent Claim
34 words
A boundary-scan-testing integrated circuit according to claim 11, wherein said active elements are constituted by MOS FETs, and data output from said second memory circuits is applied to the gates of the MOS FETs.
Claim 16
Dependent Claim
16 words
A boundary-scan-testing integrated circuit according to claim 13, wherein said MOS FETs function as pull-up resistors.
Claim 17
Dependent Claim
16 words
A boundary-scan-testing integrated circuit according to claim 13, wherein said MOS FETs function as pull-down resistors.
Claim 18
Dependent Claim
22 words
A boundary-scan-testing integrated circuit according to claim 11, wherein said first and second data selectors are each constituted by a two-input multiplexer.
Claim 19
Dependent Claim
49 words
A boundary-scan-testing integrated circuit according to claim 11, wherein the normal operation signal received by said second data selectors has a constant potential for enabling an operation of the output buffer which receives the operation control signal from said second data selectors, if the pad is an output pad.
Claim 20
Dependent Claim
45 words
A boundary-scan-testing integrated circuit according to claim 11, wherein the normal operation signal received by said second data selectors is an enable control signal supplied from the integral logic circuit and enabling ON/OFF operations of the output buffer, if the pad is an bidirectional pad.
Claim 21
Dependent Claim
30 words
A boundary-scan-testing integrated circuit according to claim 11, further comprising common connection means for directly connecting the pads which should be subjected to a parametric test on the IC chip.
Claim 22
Dependent Claim
32 words
A boundary-scan-testing integrated circuit according to claim 19, wherein said common connection means is formed on an IC chip pattern on a wafer from which IC chips are to be cut off.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-19 | 1995-11-18 | 1996-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-19 | 1999-11-18 | 2000-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-19 | 2003-11-18 | 2004-05-19 | $7700.00 | Window Closed / Lapsed |