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US5875111A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for providing a vital model of a pullup/pulldown device with delay back annotation

Assignee: Xilinx Inc
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Filing: 1997-03-25
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Granted: 1999-02-23
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Expires: 2017-03-25
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Abstract

Abstract A method of modeling a pullup device and a pulldown device with delay back annotation in accordance with the VITAL application specific integrated circuit modeling specification. The modeling method comprises the steps of modeling an entity and creating an identity primitive procedure which delays an input signal by a value specified in a timing generic and also preserves the signal shape. The procedure is then used to perform state pre-mapping of the incoming signal to preserve the identity of selected states (including all states). The delayed and pre-mapped signal forms the input to a VITAL state table to model the behavior of the device. The identity primitive procedure is then used to post-map the resulting signal in order to recover the selected states of the input signal. By altering the state pre- and post-mapping tables, either pullup or pulldown, both with delay back annotation may be modeled using the functions and procedures of the VITAL specification.

Inventors

  • 👤 Dhimant Patel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 10:23
CPC Classifications
G; G06; G06F; G06F30/00; G06F30/30; G06F30/32; G06F30/33

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 119 words
A method of modeling a device with delay back annotation in accordance with the VITAL application specific integrated circuit modeling specification; the method comprising the following steps: (a) modeling an entity with a timing generic and a port; (b) creating an identity primitive procedure for preserving selected states and delaying the input signal by a value specified in the timing generic; (c) using the identity primitive procedure, pre-mapping the input signal to preserve a set of said selected states of the input signal; (d) modeling the desired device behavior using a VITAL state table; and (e) using the identity primitive procedure, post-mapping the signal resulting from step (d) to recover said set of selected states of the input signal.
Claim 2
Independent Claim 119 words
A method of modeling a device with delay back annotation in accordance with the VITAL application specific integrated circuit modeling specification; the method comprising the following steps: (a) modeling an entity with a timing generic and a port; (b) creating an identity primitive procedure for preserving selected states and delaying the input signal by a value specified in the timing generic; (c) using the identity primitive procedure, pre-mapping the input signal to preserve a set of said selected states of the input signal; (d) modeling the desired device behavior using a VITAL state table; and (e) using the identity primitive procedure, post-mapping the signal resulting from step (d) to recover said set of selected states of the input signal.
Claim 3
Dependent Claim 31 words
A method of modeling a device as in claim 1 wherein step (b) further comprises preserving the shape of the input signal and said identity primitive is a true identity primitive.
Claim 4
Dependent Claim 17 words
A method of modeling a device as in claim 1 wherein said device is a pullup device.
Claim 5
Dependent Claim 17 words
A method of modeling a device as in claim 1 wherein said device is a pulldown device.
Claim 6
Dependent Claim 22 words
A method of modeling a device as in claim 1 wherein step (b) preserves all states of said of said input signal.

References Cited (Backward Citations)

US5581738A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-02-22 2002-08-24 2003-02-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-02-22 2006-08-24 2007-02-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-02-22 2010-08-24 2011-02-23 $7700.00 Window Closed / Lapsed

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