US3673575A
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US
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Microprogrammed common control unit with double format control words
Assignee: International Business Machines Corp
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Filing: 1970-06-29
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Granted: 1972-06-27
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Expires: 1990-06-29
Abstract
Abstract A microprogrammed common control unit for effecting the transfer of data between I/O (input/output) devices and the main storage unit of a data processing system, uses both long format control words and short format control words, the short words having half as many bit positions as the long words in the preferred embodiment, thereby minimizing the size of control storage required. Addressing of the control storage unit effects readout of one long word or a pair of short words. Predetermined bits in each control word cause transfer of a first part (half) of the next accessed long word or either one of a next accessed pair of short words to a control register for execution. If a long word has been accessed, one of said bits is effective during execution of the first part of the long word to initiate the transfer of the second word to the control register for execution after the termination of the execution of the first part of the word. Consecutive decode of the first and second portions of a long word permits a smaller control register and substantial sharing of decode circuits by different long format control word fields entered into at least partially corresponding positions of the control register, thereby effecting substantial economies.
Inventors
- 👤 Paul T Burton
- 👤 Walter E Cole
- 👤 Henry E Frassetto Jr
- 👤 Robert G Gibson
- 👤 Allan Greenberg
- 👤 Louis E Handloff
- 👤 Raymond Radlinsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:47
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/22; G06F9/26; G06F9/262; G06F9/264; G06F9/267
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
306 words
In a data processing system, a micro-programmed common control unit for controlling the transfer of data between the system main storage and input/output devices, comprising a control storage unit having a plurality of bit positions arraNged in groups of equal size for storing in each group a long format control word or alternatively a predetermined number of short format control words, each of the control words having control field bits including certain control field bits representative of its long or short format and indicative of the next control word to be accessed for execution during the next succeeding cycle, addressing apparatus effective during control word execution cycles for accessing selected ones of said groups of bit positions to read out a long format control word or alternatively a predetermined number of short format control words for the execution of a desired control word during the next control word execution cycle, a control register for receiving control field bits and having a storage bit capacity equal to the number of bit positions in a short format word, and control word execution apparatus responsive to control field bits in the control register and including first means responsive to said certain control field bits during a late portion of each control word execution cycle for gating into the control register the next desired control word in the event that it is a short format word or alternatively a selected portion of the next desired control word in the event that it is a long format word, and second means responsive to at least one of said certain control field bits during an earlier portion of each long format control word execution cycle for gating each remaining portion of the long format word into the control register in sequence for sequential execution of succeeding portions of the long format word.
Claim 2
Dependent Claim
306 words
In a data processing system, a micro-programmed common control unit for controlling the transfer of data between the system main storage and input/output devices, comprising a control storage unit having a plurality of bit positions arraNged in groups of equal size for storing in each group a long format control word or alternatively a predetermined number of short format control words, each of the control words having control field bits including certain control field bits representative of its long or short format and indicative of the next control word to be accessed for execution during the next succeeding cycle, addressing apparatus effective during control word execution cycles for accessing selected ones of said groups of bit positions to read out a long format control word or alternatively a predetermined number of short format control words for the execution of a desired control word during the next control word execution cycle, a control register for receiving control field bits and having a storage bit capacity equal to the number of bit positions in a short format word, and control word execution apparatus responsive to control field bits in the control register and including first means responsive to said certain control field bits during a late portion of each control word execution cycle for gating into the control register the next desired control word in the event that it is a short format word or alternatively a selected portion of the next desired control word in the event that it is a long format word, and second means responsive to at least one of said certain control field bits during an earlier portion of each long format control word execution cycle for gating each remaining portion of the long format word into the control register in sequence for sequential execution of succeeding portions of the long format word.
Claim 3
Dependent Claim
79 words
The common control unit of claim 1 wherein two short format words are equal in size to one long format word, and wherein said certain control field bits are equal in number to two and are contained in each short format word, the bit representative of the long or short format being contained in the first executed portion of each long format word and the other certain bit occurring in the subsequently executed portion of each long format word.
Claim 4
Dependent Claim
65 words
The common control unit of claim 2 wherein the first executed portion of each long word is characterized by the short/long format bit being a predetermined binary value, and wherein the corresponding bit position in the subsequently executed portion of each long format word is always characterized by a predetermined binary value which is the complement of the binary value of the short/long format bit.
Claim 5
Dependent Claim
190 words
In a microprogrammed common control unit operated cycle by cycle in response to microprogrammed control words of two formats, the combination comprising a control storage unit for storing a plurality of microprogrammed control words of said two formats, each of said control words containing indicators as to its format, said two formats comprising a long word format and a short word format respectively with a predetermined number of short format words being equal in size to one long format word and said indicators comprising significant bits contained in said short format words and in different portions of said long format words, a control register having a capacity for accommodating only a short format word or a predetermined portion of a long format word including their respective significant bits, and means responsive to said significant bits in said control register for causing the transfer of either a selected short format word from said control storage unit to said control register during one cycle or for consecutively transferring successive portions of each long format word to the control register during one cycle when said short and long word formats respectively are indicated.
Claim 6
Dependent Claim
190 words
In a microprogrammed common control unit operated cycle by cycle in response to microprogrammed control words of two formats, the combination comprising a control storage unit for storing a plurality of microprogrammed control words of said two formats, each of said control words containing indicators as to its format, said two formats comprising a long word format and a short word format respectively with a predetermined number of short format words being equal in size to one long format word and said indicators comprising significant bits contained in said short format words and in different portions of said long format words, a control register having a capacity for accommodating only a short format word or a predetermined portion of a long format word including their respective significant bits, and means responsive to said significant bits in said control register for causing the transfer of either a selected short format word from said control storage unit to said control register during one cycle or for consecutively transferring successive portions of each long format word to the control register during one cycle when said short and long word formats respectively are indicated.
Claim 7
Dependent Claim
72 words
The common control unit of claim 4 wherein two short format words are equal in size to one long format word, and wherein said significant bits are equal in number to two and are contained in each short format word, and in the long format word the long/shoRt bit being contained in the first transferred portion of the word and the other bit occurring in the subsequently transferred portion of the word.
Claim 8
Dependent Claim
64 words
The common control unit of claim 5 wherein the first transferred portion of each long word is characterized by the short/long format bit being a predetermined binary value, and wherein the corresponding bit position in the subsequently transferred portion of each long format word is characterized by a fixed binary value which is the complement of the binary value of the short/long format bit.
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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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |