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US3771136A Expired / Lapsed US ⏱️ 0.0 years remaining

Control unit

Assignee: International Business Machines Corp
•
Filing: 1971-04-29
•
Granted: 1973-11-06
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Expires: 1991-04-29
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Abstract

Abstract A significant cost savings is effected in a magnetic disk file control unit with a minimum loss in performance by producing a sequence of control signals, hereinafter referred to as mini-ops, for each of a large number (e.g., 39) of available file commands (often referred to as CCWs). Each mini-op is common to a large number of the commands, and it controls an integrated control unit (adaptor) or channel control unit during portions of Read, Write and Search CCW executions. The preferred embodiment of the improved control unit has been particularly adapted for use with a microprogrammed processor and each sequence of mini-ops is produced by the microprogram. A count is formed with each miniop; and, when predetermined count values are achieved in the control unit, they selectively initiate required microprogram interrupts and/or control unit control functions. There are only four mini-ops, namely: Read Data, Write Data, Write Gap, and NoOp. A mini-op is issued for each field which is to be read or written and for each gap which is to be written. No-Ops are issued as required. Prior art control units included very complex and expensive channel or adaptor hardware to decode each of the 39 commands or CCWs transferred under microprogram control from control store associated with the processor to the channel or adaptor. The use of the mini-ops simplifies and reduces substantially the hardware, yet it does not result in any appreciable degradation of the processing system.

Inventors

  • 👤 M Heneghan
  • 👤 M Hughes

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-22 21:28
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/10; G06F13/12; G06F13/122; G06F9/00; G06F9/06; G06F9/22; G06F9/226; G11; G11B; G11B20/00; G11B20/10; G11B20/12; G11B20/1217; G11B20/1252; G11B2020/1257

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 349 words
In a data processing system having a microprogrammed processor, having a unit storing each of a plurality of data records in a plurality of serially accessed field locations separated by gap locations, and having a memory for storing different write commands, different read commands and different search commands, for controlling the transfer of data between the processor and the storing unit, a control unit comprising means for receiving from the processor predetermined sequences of control words from a group consisting of read data, write data, write gap and no-op control words, word by word, for said read, write and search commands and including an operation register for storing each control word, word by word as it is received, each control word having an operation code portion and a count portion, means responsive to the operation code portion of each read data control word, write data control word and write gap control word while it is in the operation register for selectively transferring data between only a predetermined one of said locations and the control unit serially by bit, means responsive to said operation code portion of each read data and write data control word while it is in the operation register for transferring said data between the processor and the control unit by bit group, means responsive to the operation code portion of each no-op control word while it is in the operation register for inhibiting data transfer between one of said locations and the control unit, means for periodically decrementing the count portion of each read data control word, write data control word, write gap control word and no-op control word while it is in the operation register, means for terminating the data transfer for each read data control word, write data control word and write gap control word when its decremented count is at a first value, and means effective when the decremented count in each control word is at a second value for rendering the receiving means effective to receive a next succeeding control word in the sequence containing the control word in the operation register.
Claim 2
Dependent Claim 349 words
In a data processing system having a microprogrammed processor, having a unit storing each of a plurality of data records in a plurality of serially accessed field locations separated by gap locations, and having a memory for storing different write commands, different read commands and different search commands, for controlling the transfer of data between the processor and the storing unit, a control unit comprising means for receiving from the processor predetermined sequences of control words from a group consisting of read data, write data, write gap and no-op control words, word by word, for said read, write and search commands and including an operation register for storing each control word, word by word as it is received, each control word having an operation code portion and a count portion, means responsive to the operation code portion of each read data control word, write data control word and write gap control word while it is in the operation register for selectively transferring data between only a predetermined one of said locations and the control unit serially by bit, means responsive to said operation code portion of each read data and write data control word while it is in the operation register for transferring said data between the processor and the control unit by bit group, means responsive to the operation code portion of each no-op control word while it is in the operation register for inhibiting data transfer between one of said locations and the control unit, means for periodically decrementing the count portion of each read data control word, write data control word, write gap control word and no-op control word while it is in the operation register, means for terminating the data transfer for each read data control word, write data control word and write gap control word when its decremented count is at a first value, and means effective when the decremented count in each control word is at a second value for rendering the receiving means effective to receive a next succeeding control word in the sequence containing the control word in the operation register.
Claim 3
Dependent Claim 43 words
A system as claimed in claim 1 wherein the control unit includes a backup register storing at least a part of said next succeeding control word until the decremented count of the control word in the operation register is at said first value.
Claim 4
Dependent Claim 29 words
A system as claimed in claim 2 wherein the control unit includes an additional register for holding said count portion of each control word prior to each periodic decrementing.
Claim 5
Dependent Claim 43 words
A system as claimed in claim 3 wherein the control unit includes a buffer having a capacity equal to the data bit group for storing data transferred between the storing unit and the control unit and between the control unit and the processor.

References Cited (Backward Citations)

US3675209A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-11-05 1977-05-07 1977-11-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-11-05 1981-05-07 1981-11-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-11-05 1985-05-07 1985-11-06 $7700.00 Window Closed / Lapsed

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