US5514975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data output impedance control
Assignee: International Business Machines Corp
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Filing: 1995-05-15
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Granted: 1996-05-07
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Expires: 2015-05-15
Abstract
Abstract The present invention provides an apparatus and method for monitoring the functioning of a special operational mode on an integrated circuit module without the need for a special or dedicated pin. By monitoring the data output pins of the module operation in a special operational mode and premature interruption thereof, is detected. Delayed transition from a state of low impedance to a state of high impedance during the data output cycle is indicative of the special operational mode. The modules which usually have tri-state devices on their output lines are provided with delay circuitry to delay the transition of the tri-state device, during the data output cycle, from a state of low impedance to a state of high impedance while the device remains in a special operating mode.
Inventors
- 👤 Alfred L. Sartwell
- 👤 Endre P. Thoma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:32
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/31701
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
214 words
An output control circuit for monitoring an operational mode of an integrated circuit module comprising: a tri-state device with an input connection for the reception of data, an output connection for the transmission of data, and a disable control responsive to a disable signal for changing the tri-state device from a state of low impedance which allows the transmission of data to a state of high impedance which prevents the transmission of data; disable means which produces a disable signal upon completion of said operational mode, means for switching the disable signal between a first line and a second line, said first and second lines being connected to the disable control of the tri-state device, and wherein the first line allows an immediate transmission of the disable signal to said disable control and the second line has delay means for delaying the transmission of the disable signal to the disable control; detection means for detecting the initiation of the operational mode and in response thereto setting the switching means to connect the disable signal to the second line; and monitoring means for monitoring the operation of the integrated circuit module and upon detection of a premature interruption of said operational mode setting the switching means to connect the disable signal to the first line.
Claim 2
Dependent Claim
214 words
An output control circuit for monitoring an operational mode of an integrated circuit module comprising: a tri-state device with an input connection for the reception of data, an output connection for the transmission of data, and a disable control responsive to a disable signal for changing the tri-state device from a state of low impedance which allows the transmission of data to a state of high impedance which prevents the transmission of data; disable means which produces a disable signal upon completion of said operational mode, means for switching the disable signal between a first line and a second line, said first and second lines being connected to the disable control of the tri-state device, and wherein the first line allows an immediate transmission of the disable signal to said disable control and the second line has delay means for delaying the transmission of the disable signal to the disable control; detection means for detecting the initiation of the operational mode and in response thereto setting the switching means to connect the disable signal to the second line; and monitoring means for monitoring the operation of the integrated circuit module and upon detection of a premature interruption of said operational mode setting the switching means to connect the disable signal to the first line.
Claim 3
Dependent Claim
13 words
The circuit of claim 1 wherein the delay means comprises a mono-stable device.
Claim 4
Dependent Claim
13 words
The circuit of claim 1 wherein the delay means comprises a bi-stable device.
Claim 5
Dependent Claim
62 words
The circuit of claim 1 further comprising a third line, said third line including delay means for delaying transmission of the disable signal for a delay time different than a delay time of the delay means of the second line; and wherein the switching means is able to selectively connect said disable signal to any of said first, second and third lines.
Claim 6
Dependent Claim
16 words
The circuit of claim 1 wherein the operational mode to be monitored comprises a burn-in test.
Claim 7
Dependent Claim
58 words
The circuit of claim 4 wherein the switching means is set to connect the disable signal: (a) to the first line during normal operation of the module; (b) to the second line during operation of the module in a first test mode, and (c) to the third line during operation of the module in a second test mode.
Claim 8
Dependent Claim
49 words
The circuit of claim 6 wherein the switching means is reset to connect the disable signal to the first line upon detection of a premature interruption of module operation in the first test mode and upon detection of a premature interruption of module operation in the second test mode.
Claim 9
Dependent Claim
230 words
An integrated circuit module having a plurality of output lines, each of said plurality of output lines having an output control circuit associated therewith, the output control circuit comprising: a tri-state device with an input connection for the reception of data, an output connection for the transmission of data, and a disable control responsive to a disable signal for changing the tri-state device from a state of low impedance which allows the transmission of data to a state of high impedance which prevents the transmission of data; disable means which produces a disable signal, means for switching the disable signal between a first line and a second line, said first and second lines being connected to the disable control of the tri-state device, and wherein the first line allows an instantaneous transmission of the disable signal to said disable control and the second line has delay means for delaying the transmission of the disable signal to the disable control; condition detection means for detecting the initiation of a condition and in response thereto setting the switching means to connect the disable signal to the second line; and monitoring means for monitoring the condition and upon detection of a change of said condition setting the switching means to connect the disable signal to the first line, whereby different conditions can be simultaneously monitored to control the output of respective output lines.
Claim 10
Dependent Claim
230 words
An integrated circuit module having a plurality of output lines, each of said plurality of output lines having an output control circuit associated therewith, the output control circuit comprising: a tri-state device with an input connection for the reception of data, an output connection for the transmission of data, and a disable control responsive to a disable signal for changing the tri-state device from a state of low impedance which allows the transmission of data to a state of high impedance which prevents the transmission of data; disable means which produces a disable signal, means for switching the disable signal between a first line and a second line, said first and second lines being connected to the disable control of the tri-state device, and wherein the first line allows an instantaneous transmission of the disable signal to said disable control and the second line has delay means for delaying the transmission of the disable signal to the disable control; condition detection means for detecting the initiation of a condition and in response thereto setting the switching means to connect the disable signal to the second line; and monitoring means for monitoring the condition and upon detection of a change of said condition setting the switching means to connect the disable signal to the first line, whereby different conditions can be simultaneously monitored to control the output of respective output lines.
References Cited (Backward Citations)
US4907183A
Cited
US5117324A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-07 | 1999-11-06 | 2000-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-07 | 2003-11-06 | 2004-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-07 | 2007-11-06 | 2008-05-07 | $7700.00 | Window Closed / Lapsed |