System and method for increasing the output data throughput of a computer

• US 4,213,176 A
• Filed: 12/22/1976
• Issued: 07/15/1980
• Est. Priority Date: 12/22/1976
• Status: Expired due to Term

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Cooper, Paul J.
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/753,398
• Time in Patent Office: 1,301 Days
• Field of Search: 364/200 MS File, 364/900 MS File
• US Class Current: 710/1
• CPC Class Codes: G06F 13/28 using burst mode transfer, e.g. direct memory access DMA, cycle steal G06F13/32 takes precedence

Abstract

A circuit and method for increasing the output data per unit time from a computer to its associated peripheral terminals or utilization devices is disclosed in which the computer output address and data lines are time multiplexed by a novel decoding technique which enables the address bits and data bits to be interpreted together to form a new data word having a number of bits equal to the sum of the original data bits and the address bits interpreted as data bits. A plurality of decoders, each at a peripheral terminal and each having an identification address code, enable a window for decoding multiple transfers of data on output address and data lines, said window having a predetermined time duration during which all other peripheral identification address codes are locked out, until the data transfer is completed.

A microprocessor embodying the invention is also disclosed in which the output data capability is increased from eight to sixteen bits without hardware modification to the microprocessor.

Claims

1. A method of increasing the output from an n bit processor to a plurality of utilization devices wherein said processor is interconnected to said utilization devices by n data lines and m address lines wherein n and m are whole integers, comprising the steps of:

(a) forming data words having a length equal to n plus m data bits for data to be transferred to a selected one of said utilization devices and determining a count of said data words to be transferred;

(b) selecting said utilization device which is to receive said data words and disabling the remaining non-selected utilization devices for a predetermined time interval;

(c) entering said count on a counter means;

(d) transferring said data words over said n data lines and m address lines during said predetermined time interval; and

(e) ending said predetermined time interval when said count of data words to be transferred has been transferred to said selected utilization device.

2. The method as claimed in claim 1 in which said selecting step (b) also includes the step of dedicating said processor to said transferring step (d) until said count of data words has been transferred to said selected utilization device.

3. A processing system comprising:

a processor;

a plurality of utilization devices;

address lines and data lines operatively interconnecting said processor with said plurality of utilization devices;

means for storing data words and a count of said data words to be transferred to a selected one of said utilization devices over said address and data lines;

means for selecting one of said utilization devices and disabling the remaining non-selected said utilization devices for a predetermined time interval;

means for receiving said data words transferred over said address lines and said data lines during said predetermined time interval thereby increasing the output of said processor;

said predetermined time interval expiring upon the completion of said count of said data words transferred to said selected utilization device.

4. The system as claimed in claim 3 in which said processor is an n bit processor which normally processes n bits of data and transmits n bits of data over n said data lines to a selected one of said utilization devices which is addressed by said address lines, said system including m said address lines wherein n and m are whole integers, and wherein said data words are made up of n plus m data bits.

5. The system as claimed in claim 4 in which said selecting means includes a counting means which causes said predetermined time interval to expire upon the completion of said count of data words which are transferred to said selected utilization device.

6. The system as claimed in claim 5 in which said processor is an 8 bit microprocessor having 8 said data lines and 8 said address lines operatively interconnected therewith, and said data words are made of 16 bits.

7. A processing system comprising:

an n bit microprocessor;

a plurality of utilization devices;

n data lines and m address lines operatively interconnecting said microprocessor with said plurality of utilization devices wherein n and m are whole integers;

means for storing data words and a count of said data words to be transferred to a selected one of said utilization devices wherein the length of each said data words is equal to n plus m data bits;

means for selecting one of said utilization devices and disabling all the remaining non-selected said utilization devices for a predetermined time interval;

means for receiving said data words transferred over said data lines and said address lines during said predetermined time interval;

said predetermined time interval expiring upon the completion of said count of said data words transferred to said selected utilization device.

8. The system as claimed in claim 7 in which said selecting means includes a counting means upon which said count is registered to initiate the start of said predetermined time interval, and which said counting means terminates said predetermined time interval upon said count of said data words being transferred over said data lines and said address lines to said selected utilization device.

9. The system as claimed in claim 7 in which said selecting means comprises:

decode logic means for detecting when said system is to operate in a special mode;

counter means upon which said count is registered to initiate the start of said predetermined time interval for said special mode and which said counting means terminates said predetermined time interval upon said count of data words being transferred over said data lines and said address lines to said selected utilization device;

said decode logic means also producing an interrupt disable signal to dedicate said microprocessor during said predetermined time interval to the transferrence of said data words,

said counter means, upon completion of said count of data words being transferred to said selected utilization device, issuing a reset signal to terminate said special mode.

10. A processing system comprising:

an n bit microprocessor;

a plurality of utilization devices;

n data lines and m address lines operatively interconnecting said microprocessor with said plurality of utilization devices wherein n and m are whole integers;

means for storing data words and a count of said data words to be transferred to a selected one of said utilization devices wherein the length of each said data word is equal to n plus m data bits;

means for selecting one of said utilization devices and disabling all the remaining non-selected said utilization devices for a predetermined time interval;

means for receiving said data words transferred over said data lines and said address lines during said predetermined time interval;

said predetermined time interval expiring upon the completion of said count of said data words

11. A circuit means for use with a processor for increasing the output of said processor to a plurality of utilization devices in which said processor is an n bit processor comprising:

n data lines and m address lines operatively interconnecting said processor with said utilization devices wherein n and m are whole integers;

means for storing data words and a count of said data words to be transferred to a selected one of said utilization devices wherein the length of said data words is equal to n plus m data bits;

means for selecting one of said utilization devices and disabling the remaining non-selected utilization devices for a predetermined time interval;

means for receiving said data words transferred over said data lines and same address lines during said predetermined time interval;

said predetermined time interval expiring upon the completion of said count of said data words transferred to said selected utilization device.

12. The circuit as claimed in claim 11 in which said selecting means includes a counting means which causes said predetermined time interval to expire upon the completion of said count of data words which are transferred to said selected utilization device.

13. The circuit as claimed in claim 11 in which said selecting means comprises:

decode logic means for detecting when said system is to operate in a special mode;

counter means upon which said count is registered to initiate the start of said predetermined time interval for said special mode and which said counting means terminates said fixed predetermined time interval upon said count of data words being transferred over said data lines and said address lines to said selected utilization device;

said decode logic means also producing an interrupt disable signal to dedicate said processor during said predetermined time interval to the transferrence of said data words,

said counter means, upon completion of said count of data words being transferred to said selected utilization device, issuing a reset signal to terminate said special mode.

14. A circuit means for use with a processor for increasing the output of said processor to a plurality of utilization devices in which said processor is an n bit processor comprising:

n data lines and m address lines operatively interconnecting said processor with said utilization devices wherein n and m are whole integers;

means for storing data words and a count of said data words to be transferred to a selected one of said utilization devices wherein the length of said data words is equal to n plus m data bits;

means for selecting one of said utilization devices and disabling the remaining non-selected utilization devices for a predetermined time interval;

means for receiving said data words transferred over said data lines and said address lines during said predetermined time interval;

said predetermined time interval expiring upon the completion of said count of said data words transferred to said selected utilization device;

said selecting means comprising;

decode logic means for detecting when said system is to operate in a special mode;

counter means upon which said count is registered to initiate the start of said predetermined time interval for said special mode and which said counter means terminates said fixed predetermined time interval upon said count of data words being transferred over said data lines and said address lines to said selected utilization device;

transferred to said selected utilization device;

said selecting means comprising;

decode logic means for detecting when said system is to operate in a special mode;

counter means upon which said count is registered to initiate the start of said predetermined time interval for said special mode and which said counter means terminates said predetermined time interval upon said count of data words being transferred over said data lines and said address lines to said selected utilization device;

said decode logic means also producing an interrupt disable signal to dedicate said microprocessor during said predetermined time interval to the transferrence of said data words,

said counter means, upon completion of said count of data words being transferred to said selected utilization device, issuing a reset signal to terminate said special mode;

said counter means including a down counter, and said decode logic means being buffered, and said receiving means including parallel to serial shift register means.

said decode logic means also producing an interrupt disable signal to dedicate said processor during said predetermined time interval to the transferrence of said data words,

said counter means, upon completion of said count of data words being transferred to said selected utilization device, issuing a reset signal to terminate said special mode;

said counter means including a down counter, and said decode logic means being buffered, and said receiving means including parallel to serial shift register means.