US3800293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microprogram control subsystem
Assignee: International Business Machines Corp
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Filing: 1972-12-26
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Granted: 1974-03-26
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Expires: 1992-12-26
Abstract
Abstract A microprogram control subsystem discloses two control stores, one of which is accessed and utilized only on the first cycle of a microprogram sequence utilized to execute an information handling system instruction. A portion of the operation code of the system instruction is used to address the first-cycle control store to provide access to a microinstruction having fewer binary bits than normal microinstructions, and is effective to direct access to the remainder of the microprogram sequence contained in the other control store.
Inventors
- 👤 T Enger
- 👤 C Evans
- 👤 L Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:49
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/22; G06F9/26; G06F9/262; G06F9/264; G06F9/267
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
162 words
A cyclically operable microprogram control subsystem for an information handling system for controlling system operations in response to system conditions and system instructions including at least a plural binary bit operation code comprising: a first control store for microinstructions; a second control store for microinstructions; each said first and second control stores including addressing means and gating means for providing access to system controlling microinstructions; control register means connected to said gating means of said first control store and said second control store for receiving and manifesting microinstructions for each of plural control subsystem cycles of operation; and selection means, connected and responsive to microinstructions manifested by said control register means, including first enabling means connected to said gating means of said first control store and second enabling means connected to said gating means of said second control store, said first control store enabling means including last cycle signal means for indicating the last control subsystem cycle of a system instruction execution.
Claim 2
Dependent Claim
162 words
A cyclically operable microprogram control subsystem for an information handling system for controlling system operations in response to system conditions and system instructions including at least a plural binary bit operation code comprising: a first control store for microinstructions; a second control store for microinstructions; each said first and second control stores including addressing means and gating means for providing access to system controlling microinstructions; control register means connected to said gating means of said first control store and said second control store for receiving and manifesting microinstructions for each of plural control subsystem cycles of operation; and selection means, connected and responsive to microinstructions manifested by said control register means, including first enabling means connected to said gating means of said first control store and second enabling means connected to said gating means of said second control store, said first control store enabling means including last cycle signal means for indicating the last control subsystem cycle of a system instruction execution.
Claim 3
Dependent Claim
64 words
A microprogram control subsystem in accordance with claim 1 further including: operation code register means; and first interconnecting means from said operation code register means to said addressing means of said first control store whereby the first microinstruction manifested by said control register means for each system instruction execution is accessed from said first control store in accordance with the system instruction operation code.
Claim 4
Dependent Claim
63 words
A microprogram control subsystem in accordance with claim 2 including: second interconnecting means for transferring manifestations of a next address from each microinstruction in said control register to said addressing means of said second control store, whereby the address of the initial access to said second control store for each system instruction is manifested by a microinstruction accessed from said first control store.
Claim 5
Dependent Claim
172 words
A microprogram control subsystem in accordance with claim 3 wherein: said second control store is comprised of a plurality of control store modules, each responsive to said addressing means to provide access to a microinstruction; said gating means of said second control store is comprised of a like plurality of gate elements, each connecting one of said control store modules to said control register; said selection means includes branch control logic responsive to branch control manifestations in each microinstructions in said control register, and system condition signalling means, for selectively enabling one of said gate elements; said first interconnecting means includes means for transferring a portion of the binary bits of an operation code, representing the designation of a group of operation codes; and third interconnecting means for transferRing the remaining binary bits of the operation code in said operation code register to said branch control logic to thereby enable one of said gate elements to select the second microinstruction for each system instruction execution from one of said control store modules.
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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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |