Patent US3573853A successfully refreshed from Google Patents.
US3573853A
Expired / Lapsed
US
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Look-ahead control for operation of program loops
Assignee: Texas Instruments Inc
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Filing: 1968-12-04
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Granted: 1971-04-06
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Expires: 1988-12-04
Abstract
Abstract A programmed computer look-ahead system is responsive to the presence in the instruction stream of a look-ahead instruction which is followed after a predetermined number of instructions by a conditional branch instruction. A decoder responds to the lookahead instruction to establish an index which is then changed an equal amount for each instruction processed. In response to a stored conditional branch instruction the operation returns to the instruction stream at the location of the stored look-ahead address when the index changes by an amount representative of the spacing along the instruction stream between the look-ahead instruction and conditional branch instruction.
Inventors
- 👤 William J Watson
- 👤 Thomas E Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:14
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/30; G06F9/38; G06F9/3802; G06F9/3808; G06F9/381
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
81 words
In a look-ahead system for a programmable digital computer the combination which comprises: a. means responsive to a look-ahead instruction included within the instruction stream for establishing an initial condition in said computer; b. means responsive to each instruction processed following said look-ahead instruction for modifying said condition incrementally; and c. means for conditionally directing the look-ahead system to return to the instruction stream at the location of the lookahead instruction when said condition changes by a predetermined number of increments.
Claim 2
Dependent Claim
81 words
In a look-ahead system for a programmable digital computer the combination which comprises: a. means responsive to a look-ahead instruction included within the instruction stream for establishing an initial condition in said computer; b. means responsive to each instruction processed following said look-ahead instruction for modifying said condition incrementally; and c. means for conditionally directing the look-ahead system to return to the instruction stream at the location of the lookahead instruction when said condition changes by a predetermined number of increments.
Claim 3
Dependent Claim
86 words
In a look-ahead system for a programmable digital computer for the combination which comprises: a. a counter and a decode means responsive to a look-ahead instruction word included within the instruction stream for initializing said counter; b. means to change said counter in response to each instruction following said look-ahead instruction word; and c. means for conditionally directing the look-ahead system to return to the instruction stream at the location of the look-ahead instruction when the counter changes from its initialized condition a predetermined counter value.
Claim 4
Dependent Claim
86 words
In a look-ahead system for a programmable digital computer for the combination which comprises: a. a counter and a decode means responsive to a look-ahead instruction word included within the instruction stream for initializing said counter; b. means to change said counter in response to each instruction following said look-ahead instruction word; and c. means for conditionally directing the look-ahead system to return to the instruction stream at the location of the look-ahead instruction when the counter changes from its initialized condition a predetermined counter value.
Claim 5
Dependent Claim
33 words
The combination set forth in claim 2 in which means are provided for fetching instructions from memory in blocks of instructions and for serially applying instructions from each block to said decode means.
Claim 6
Dependent Claim
113 words
A look-ahead method for use in a programmable digital computer which comprises: a. inserting a look-ahead instruction into an instruction stream to include a code signifying a predetermined count; b. inserting a conditional branch instruction in said instruction stream displaced downstream from said look-ahead instruction by said predetermined count; c. in response to fetching of said look-ahead instruction form memory, establishing an index representative of said predetermined count; d. changing said index one increment for each instruction processed; e. storing the address of said look-ahead instruction; and f. returning to said instruction stream at the location of the stored look-ahead address when said index changes by an amount representative of said predetermined amount.
Claim 7
Dependent Claim
113 words
A look-ahead method for use in a programmable digital computer which comprises: a. inserting a look-ahead instruction into an instruction stream to include a code signifying a predetermined count; b. inserting a conditional branch instruction in said instruction stream displaced downstream from said look-ahead instruction by said predetermined count; c. in response to fetching of said look-ahead instruction form memory, establishing an index representative of said predetermined count; d. changing said index one increment for each instruction processed; e. storing the address of said look-ahead instruction; and f. returning to said instruction stream at the location of the stored look-ahead address when said index changes by an amount representative of said predetermined amount.
Claim 8
Dependent Claim
39 words
The method of claim 4 wherein said predetermined count equals the number of instructions in said stream between said look-ahead instruction and said branch instruction and wherein said index is decremented to zero, an increment for each said instruction.
References Cited (Backward Citations)
USRE26087E
Cited
US3312951A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |