US5301165A
Expired / Lapsed
US
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Chip select speedup circuit for a memory
Assignee: International Business Machines Corp
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Filing: 1992-10-28
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Granted: 1994-04-05
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Expires: 2012-10-28
Abstract
Abstract A memory circuit is provided which has a select and a deselect mode. The memory circuit, as part of its technique for quickly accessing data, includes circuitry for generating a pulse in response to detecting an address transition. When the memory circuit switches from the deselect mode to select mode, there appears to be an address transition even when there is not an address transition. In order to prevent a delay associated with interpreting such a false transition as an actual transition, local clock pulse generators are used which only detect high to low transitions in the chip select mode.
Inventors
- 👤 Michael K. Ciraula
- 👤 Christopher M. Durham
- 👤 Derwin L. Jallice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:33
CPC Classifications
G; G11; G11C; G11C8/00; G11C8/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
91 words
A memory circuit which is enabled in response to an occurrence of a chip select signal, comprising: a plurality of address input means, each for receiving an address signal and being enabled in response to an occurrence of a chip select signal; transition detection means coupled to the plurality of address input means, for detecting transition of an address signal: and signal pulse generation means for producing a clock pulse in response to an address transition, the pulse generated only on detection of a falling edge of the address transition signal.
Claim 2
Dependent Claim
91 words
A memory circuit which is enabled in response to an occurrence of a chip select signal, comprising: a plurality of address input means, each for receiving an address signal and being enabled in response to an occurrence of a chip select signal; transition detection means coupled to the plurality of address input means, for detecting transition of an address signal: and signal pulse generation means for producing a clock pulse in response to an address transition, the pulse generated only on detection of a falling edge of the address transition signal.
Claim 3
Dependent Claim
156 words
A memory circuit which, in response to a chip select signal switching from a first logic state to a second logic state, provides data selected by a plurality of address signals, comprising: a plurality of address input means enabled by the second logic state of the chip select signal and disabled by the first logic state of the chip select signal, each address input means for receiving a corresponding address signal, for providing an output signal representative of the received address signal when enabled by the chip select signal, and for providing the output signal in a predetermined state when disabled by the select signal: a plurality of transition detection means, each coupled to a corresponding address input means for detecting a transition of the output signal of the corresponding address input means: and disabling means for disabling all of the transition detection means until a falling edge signal from the address transition detectors is obtained.
Claim 4
Dependent Claim
156 words
A memory circuit which, in response to a chip select signal switching from a first logic state to a second logic state, provides data selected by a plurality of address signals, comprising: a plurality of address input means enabled by the second logic state of the chip select signal and disabled by the first logic state of the chip select signal, each address input means for receiving a corresponding address signal, for providing an output signal representative of the received address signal when enabled by the chip select signal, and for providing the output signal in a predetermined state when disabled by the select signal: a plurality of transition detection means, each coupled to a corresponding address input means for detecting a transition of the output signal of the corresponding address input means: and disabling means for disabling all of the transition detection means until a falling edge signal from the address transition detectors is obtained.
Claim 5
Dependent Claim
136 words
In a memory circuit which is enabled in response to an occurrence of a chip select signal, and which comprises: input means for receiving an address signal and providing an output responsive thereto when enabled by an occurrence of the chip select signal, and providing the output at a predetermined state when disabled by the chip select signal: transition detection means, coupled to the input means for detecting a transition of the address signal: and an equalization pulse generator means, coupled to the transition detection means, for generating an equalization pulse in response to the transition detection means detecting a transition of the address signal: a method comprising the steps of: preventing the detection means from detecting a transition of the address signal because there is no leading edge transition to the detected address transition signal.
Claim 6
Dependent Claim
136 words
In a memory circuit which is enabled in response to an occurrence of a chip select signal, and which comprises: input means for receiving an address signal and providing an output responsive thereto when enabled by an occurrence of the chip select signal, and providing the output at a predetermined state when disabled by the chip select signal: transition detection means, coupled to the input means for detecting a transition of the address signal: and an equalization pulse generator means, coupled to the transition detection means, for generating an equalization pulse in response to the transition detection means detecting a transition of the address signal: a method comprising the steps of: preventing the detection means from detecting a transition of the address signal because there is no leading edge transition to the detected address transition signal.
Claim 7
Dependent Claim
18 words
The memory circuit of claim 2, wherein the chip select signal has both true and complement logic values.
Claim 8
Dependent Claim
18 words
The circuit of claim 2, wherein the plurality of address input means are summed in a OR gate.
Claim 9
Dependent Claim
32 words
The memory circuit of claim 2, wherein the output of the transition detection means is combined in a summer whose output is used as a write line enable for the memory circuit.
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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) | 1997-04-04 | 1997-10-04 | 1998-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-04 | 2001-10-04 | 2002-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-04 | 2005-10-04 | 2006-04-05 | $7700.00 | Window Closed / Lapsed |