Patent US6401213B1 successfully refreshed from Google Patents.
US6401213B1
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Timing circuit for high speed memory
Assignee: Round Rock Research LLC
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Filing: 1999-07-09
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Granted: 2002-06-04
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Expires: 2019-07-09
Abstract
Abstract A timing circuit to adjust a data strobe signal received from a synchronous memory includes a delay circuit to adjustably delay the data strobe signal and to generate a delayed data strobe signal, a clock capture register to sample the delayed data strobe signal and to generate a sampled clock signal, a data capture register to sample a read data signal from the synchronous memory and to generate a sampled data signal, and an analysis circuit to determine a timing relationship between the sampled clock signal and the sampled data signal and to adjust the delay circuit based on the determined timing relationship. By way of example, the determined timing relationship may be used to delay the read data strobe signal so that it transitions (e.g., from a low state to a high state) in the middle of the data signal's data eye.
Inventors
- 👤 Joseph M. Jeddeloh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:16
CPC Classifications
G; G06; G06F; G06F5/00; G06F5/06; G11; G11C; G11C7/00; G11C7/22; G11C7/222
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
106 words
A timing circuit to adjust a data strobe signal received from a synchronous memory, the timing circuit comprising: a delay circuit to adjustably delay the data strobe signal and to generate a delayed data strobe signal; a clock capture register to sample the delayed data strobe signal and to generate a sampled clock signal; a data capture register to sample a read data signal from the synchronous memory and to generate a sampled data signal; and an analysis circuit to determine a timing relationship between the sampled clock signal and the sampled data signal and to adjust the delay circuit based on the determined timing relationship.
Claim 2
Dependent Claim
106 words
A timing circuit to adjust a data strobe signal received from a synchronous memory, the timing circuit comprising: a delay circuit to adjustably delay the data strobe signal and to generate a delayed data strobe signal; a clock capture register to sample the delayed data strobe signal and to generate a sampled clock signal; a data capture register to sample a read data signal from the synchronous memory and to generate a sampled data signal; and an analysis circuit to determine a timing relationship between the sampled clock signal and the sampled data signal and to adjust the delay circuit based on the determined timing relationship.
Claim 3
Dependent Claim
16 words
The timing circuit of claim 1 , wherein the delay circuit comprises a programmable delay line.
Claim 4
Dependent Claim
32 words
The timing circuit of claim 2 , wherein the delay line provides a delay of between approximately zero seconds and a time approximately equal to a period of the data strobe signal.
Claim 5
Dependent Claim
56 words
The timing circuit of claim 1 , further comprising a clock generator to generate a plurality of clock signals from the delayed data strobe signal, a first portion of said plurality of clock signals coupled to the clock capture register and a second portion of said plurality of clock signals coupled to the data capture register.
Claim 6
Dependent Claim
26 words
The timing circuit of claim 4 , wherein the clock generator comprises an N-tap delay line, each tap providing one of the plurality of clock signals.
Claim 7
Dependent Claim
26 words
The timing circuit of claim 5 , wherein the first portion and the second portion of said plurality of clock signals comprise all N clock signals.
Claim 8
Dependent Claim
44 words
The timing circuit of claim 6 , wherein the clock capture register comprises N storage elements to generate an N-bit sampled clock signal, each of the N storage elements being driven by a corresponding one of the N clock signals from the clock generator.
Claim 9
Dependent Claim
44 words
The timing circuit of claim 6 , wherein the data capture register comprises N storage elements to generate an N-bit sampled data signal, each of the N storage elements being driven by a corresponding one of the N clock signals from the clock generator.
Claim 10
Dependent Claim
42 words
The timing circuit of claim 6 , further comprising a trigger circuit to generate a trigger signal, the trigger signal causing the clock capture register to generate the sampled clock signal and the data capture register to generate the sampled data signal.
Claim 11
Dependent Claim
28 words
The timing circuit of claim 9 , wherein the trigger signal is generated when a specified pattern is detected by the trigger circuit on the read data signal.
Claim 12
Dependent Claim
19 words
The timing circuit of claim 10 , wherein the specified pattern comprises a high-to-low-to-high transition or a low-to-high-to-low transition.
Claim 13
Dependent Claim
30 words
The timing circuit of claim 11 , wherein the analysis circuit determines when the delayed data strobe signal transitions with respect to the low-to-high transition of the read data signal.
Claim 14
Dependent Claim
50 words
The timing circuit of claim 12 , wherein the analysis circuit causes the delay circuit to delay the data strobe signal so that the delayed data strobe signal transitions from a low state to a high state approximately in the middle of a data eye of the read data signal.
Claim 15
Dependent Claim
53 words
A computer system motherboard comprising: a processor socket adapted to receive a processor module; at least one memory socket adapted to receive a memory module; a bridge circuit coupled to the processor socket and the at least one memory socket, the bridge circuit having a timing circuit in accordance with claim 1 .
Claim 16
Dependent Claim
18 words
The computer system motherboard of claim 14 , further comprising a system bus coupled to the bridge circuit.
Claim 17
Dependent Claim
25 words
The computer system motherboard of claim 15 , wherein at least one of said at least one memory socket are coupled to a memory module.
Claim 18
Dependent Claim
16 words
The computer system of claim 16 , wherein the memory module comprises synchronous random access memory.
Claim 19
Independent Claim
56 words
A method to adjust a data strobe signal comprising: receiving a read data strobe signal and a data signal from a synchronous memory device during a memory read operation; determining a timing characteristic between the read data strobe signal and the data signal; and delaying the read data strobe signal based on the measured timing characteristic.
Claim 20
Independent Claim
56 words
A method to adjust a data strobe signal comprising: receiving a read data strobe signal and a data signal from a synchronous memory device during a memory read operation; determining a timing characteristic between the read data strobe signal and the data signal; and delaying the read data strobe signal based on the measured timing characteristic.
Claim 21
Dependent Claim
47 words
The method of claim 18 , wherein the act of determining comprises: delaying the read data strobe signal to generate a first signal; and determining when the first signal transitions from a first state to a second state relative to a specified state of the data signal.
Claim 22
Dependent Claim
20 words
The method of claim 19 , wherein the first-state comprises a low state, the second state comprises a high state.
Claim 23
Dependent Claim
14 words
The method of claim 20 , wherein the specified state comprises a low state.
Claim 24
Dependent Claim
52 words
The method of claim 19 , wherein the act of delaying the read data strobe signal comprises delaying the read data strobe signal so that the first signal transitions from the first state to the second state approximately in the middle of the time the data signal is in the specified state.
Claim 25
Independent Claim
73 words
A method to adjust a data strobe signal comprising: receiving a read data strobe signal and a data signal from a synchronous memory device during a memory read operation; delaying the read data strobe signal to generate a delayed data strobe signal; sampling the delayed data strobe signal; sampling the data signal; and adjusting the delaying of the data strobe signal based on the sampling of the delayed data strobe and data signals.
Claim 26
Independent Claim
73 words
A method to adjust a data strobe signal comprising: receiving a read data strobe signal and a data signal from a synchronous memory device during a memory read operation; delaying the read data strobe signal to generate a delayed data strobe signal; sampling the delayed data strobe signal; sampling the data signal; and adjusting the delaying of the data strobe signal based on the sampling of the delayed data strobe and data signals.
Claim 27
Dependent Claim
52 words
The method of claim 23 , wherein the act of sampling the read data strobe signal comprises: delaying the read data strobe signal to generate a first signal; and determining when the first signal transitions from a first state to a second state relative to a specified state of the data signal.
Claim 28
Dependent Claim
20 words
The method of claim 24 , wherein the first-state comprises a low state, the second state comprises a high state.
Claim 29
Dependent Claim
14 words
The method of claim 25 , wherein the specified state comprises a low state.
Claim 30
Dependent Claim
52 words
The method of claim 24 , wherein the act of delaying the read data strobe signal comprises delaying the read data strobe signal so that the first signal transitions from the first state to the second state approximately in the middle of the time the data signal is in the specified state.
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) | 2005-06-03 | 2005-12-03 | 2006-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-06-03 | 2009-12-03 | 2010-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-06-03 | 2013-12-03 | 2014-06-04 | $7700.00 | Window Closed / Lapsed |