Process and apparatus employing microprogrammed control commands for transferring information between a control processor and communications channels
First Claim
1. In a data processing system including a main memory and a plurality of communication channels, said system having a central processing unit and a microprogrammed communication processor including a control element having a program memory storing microprogram instructions to enable said processor to control the transfer of data between said main memory and the other elements of said system, including said central processing unit and said communication channels, a machine implemented process in which said processor is controlled by said stored microprogram instructions to perform the method steps of:
- A. determining whether said central processing unit has issued a control instruction to said processor;
B. executing said control instruction if said step of determining indicates that said control instruction has been issued;
C. repeating said steps of determining and executing until said step of determining indicates that said control instruction is not presently issued;
D. determining, if no control instruction is detected during step A, whether one of said channels requires servicing;
E. servicing a said channel requiring servicing if said last-mentioned step of determining indicates such service requirement;
F. repeating said steps of determining, executing, repeating, determining, and servicing until a determination is made that a said channel does not require servicing;
G. accessing control commands associated with a first said communication channel if there is no indication that a channel requires servicing;
H. servicing said first channel if its said control commands indicate that the execution of said control commands is required;
I. repeating said first step of determining and the further steps following said first step of determining until said step of accessing is entered again;
J. repeating said step of accessing for a second said channel;
K. repeating said second mentioned step of servicing for said second said channel; and
L. reentering said first step of determining.
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Accused Products
Abstract
Firmware generated commands provided by a control store in a microprogrammed communications processor which is coupled in a system including a main memory and a central processing unit control the processing of instructions from the central processing unit, interrupts from the communications channels and servicing of such channels if a channel status change is detected. The firmware also controls the operation of the servicing of such channels by providing a control mechanism by which data is read from or written into the main memory. Further, interrupts which are not handled immediately are handled in a deferred interrupt arrangement.
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Citations
14 Claims
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1. In a data processing system including a main memory and a plurality of communication channels, said system having a central processing unit and a microprogrammed communication processor including a control element having a program memory storing microprogram instructions to enable said processor to control the transfer of data between said main memory and the other elements of said system, including said central processing unit and said communication channels, a machine implemented process in which said processor is controlled by said stored microprogram instructions to perform the method steps of:
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A. determining whether said central processing unit has issued a control instruction to said processor; B. executing said control instruction if said step of determining indicates that said control instruction has been issued; C. repeating said steps of determining and executing until said step of determining indicates that said control instruction is not presently issued; D. determining, if no control instruction is detected during step A, whether one of said channels requires servicing; E. servicing a said channel requiring servicing if said last-mentioned step of determining indicates such service requirement; F. repeating said steps of determining, executing, repeating, determining, and servicing until a determination is made that a said channel does not require servicing; G. accessing control commands associated with a first said communication channel if there is no indication that a channel requires servicing; H. servicing said first channel if its said control commands indicate that the execution of said control commands is required; I. repeating said first step of determining and the further steps following said first step of determining until said step of accessing is entered again; J. repeating said step of accessing for a second said channel; K. repeating said second mentioned step of servicing for said second said channel; and L. reentering said first step of determining. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A data processing system including a main memory and a plurality of communication channels, said system having a central processing unit and a microprogrammed communication processor including a control element having a program memory storing microprogram instructions and means for applying said microprogram instructions to said processor to enable said processor to control the transfer of data between said main memory and the other elements of said system, including said central processing unit and said communication channels, said processor further comprising the following elements responsive to said microprogram instructions to perform the operations indicated:
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A. first means for determining whether said central processing unit has issued a control instruction to said processor; B. means for executing said control instruction if there is an indication that said control instruction has been issued; C. means for enabling said means for determining and said means for executing until it is determined that a said control instruction is not presently issued; D. means for determining whether one of said channels requires servicing; E. means for servicing a said channel requiring servicing if it is determined that there is such service requirement; F. means for enabling said means for determining, executing, enabling, determining, and servicing until a determination is made that a said channel does not require servicing; G. means for accessing control commands associated with a first said communications channel if there is no indication that a channel requires servicing; H. means for servicing said first channel if its said control commands indicate that the execution of said control commands is required; I. means for enabling said first means for determining and said means A through F responsive thereto until said means for accessing is again entered; J. means for enabling the means for accessing for a second said channel; K. means for enabling means H for servicing for said second said channel; and L. means for reenabling said first means for determining after the servicing of said second said channel. - View Dependent Claims (12, 13, 14)
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Specification