US4486833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microprocessor peripheral control circuit
Assignee: Avaya Technology LLC
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Filing: 1982-09-30
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Granted: 1984-12-04
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Expires: 2002-09-30
Abstract
Abstract Microcomputers are typically designed having a cycle time during which peripheral devices are accessed. This cycle is subdivided such that during a device access certain signals sequentially are activated to control the flow of data to or from the device over a set of special purpose leads. There is disclosed an arrangement for use when the device cannot respond within the allotted cycle for controlling the device access so that multiple successive cycles are used for a single device access. In this manner the microcomputer's speed is independent from the device response speed.
Inventors
- 👤 Douglas S. Daudelin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:34
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/42; G06F13/4204; G06F13/4234; G06F13/4243
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
The method of accessing peripheral devices from a microcomputer over pre-programmed leads where the access time of some of the devices is slower than the normal access instruction cycle time of the microcomputer, said method comprising the steps of for certain of said devices applying, during a single instruction cycle of said microcomputer, to said pre-programmed leads certain access control signals timed in accordance with the internal clock of said microcomputer, and for other slower devices, applying to said pre-programmed leads, during a first microcomputer instruction cycle, a first subset of said certain access control signals, and applying to said pre-programmed leads, during subsequent microcomputer instruction cycles, other subsets of said access control signals.
Claim 2
Independent Claim
114 words
The method of accessing peripheral devices from a microcomputer over pre-programmed leads where the access time of some of the devices is slower than the normal access instruction cycle time of the microcomputer, said method comprising the steps of for certain of said devices applying, during a single instruction cycle of said microcomputer, to said pre-programmed leads certain access control signals timed in accordance with the internal clock of said microcomputer, and for other slower devices, applying to said pre-programmed leads, during a first microcomputer instruction cycle, a first subset of said certain access control signals, and applying to said pre-programmed leads, during subsequent microcomputer instruction cycles, other subsets of said access control signals.
Claim 3
Dependent Claim
40 words
The invention set forth in claim 1 wherein said first-mentioned applying step includes the sequencing through a set of pre-established micro-instructions, each micro-instruction controlling signals on said pre-programmed leads, said set of pre-established micro-instructions occurring within a single instruction cycle.
Claim 4
Dependent Claim
24 words
The invention set forth in claim 2 wherein said set of pre-established micro-instructions are contained within said microcomputer and invoked under external signal control.
Claim 5
Dependent Claim
33 words
The invention set forth in claim 1 wherein said subsets of said access control signals are generated by said microcomputer sequentially during separate microcomputer clock cycles under control of separately provided user instructions.
Claim 6
Dependent Claim
108 words
A circuit for accessing peripheral devices from a microcomputer over pre-programmed leads where the access time of some of the devices is slower than the normal access instruction cycle time of the microcomputer, said circuit comprising, first means operative during a single instruction cycle of said microcomputer, for applying to said pre-programmed leads certain access control signals timed in accordance with internal clock of said microcomputer, and second means for applying to said pre-programmed leads, during a first microcomputer instruction cycle a first subset of said access control signals, and for applying to said pre-programmed leads during subsequent microcomputer instruction cycles other subsets of said access control signals.
Claim 7
Dependent Claim
108 words
A circuit for accessing peripheral devices from a microcomputer over pre-programmed leads where the access time of some of the devices is slower than the normal access instruction cycle time of the microcomputer, said circuit comprising, first means operative during a single instruction cycle of said microcomputer, for applying to said pre-programmed leads certain access control signals timed in accordance with internal clock of said microcomputer, and second means for applying to said pre-programmed leads, during a first microcomputer instruction cycle a first subset of said access control signals, and for applying to said pre-programmed leads during subsequent microcomputer instruction cycles other subsets of said access control signals.
Claim 8
Dependent Claim
40 words
The invention set forth in claim 5 wherein said first means includes means for sequencing through a set of pre-established micro-instructions, each instruction controlling signals on said pre-programmed leads, said set of pre-established micro-instructions occurring within a single instruction cycle.
Claim 9
Dependent Claim
21 words
The invention set forth in claim 6 further comprising means for invoking said set of pre-established micro-instructions under external signal control.
Claim 10
Dependent Claim
28 words
The invention set forth in claim 6 wherein said second means includes means for controlling said subsets of said access control signals sequentially under separately provided user instructions.
References Cited (Backward Citations)
US4050096A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |