Instruction processing unit for program branches

Claim 1

IN A DATA PROCESSING SYSTEM OF THE CLASS DESCRIBED HAVING A MAIN DATA STORAGE UNIT, AN INSTRUCTION UNIT AND AN EXECUTION UNIT, SAID INSTRUCTION UNIT INCLUDING A PLURALITY OF DEVICES EACH SETTABLE IN TURN FROM SAID MAIN DATA STORAGE UNIT IN ACCORDANCE WITH THE DATA OF A CORRESPONDING INSTRUCTION OF A DATA PROCESSING PROGRAM IN SAID STORAGE UNIT TO EACH PROVIDE A BUFFER FOR AN INSTRUCTION TO BE DECODED AND A DECODING UNIT TO INSPECT AND DECODE EACH BUFFERED INSTRUCTION IN TURN, TO TRANSMIT SAID INSTRUCTION TO SAID EXECUTION UNIT FOR SUBSEQUENT EXECUTION, AND TO CONTROL SAID MAIN STORAGE UNIT TO CAUSE TRANSMISSION OF REQUIRED OPERANDS TO SAID EXECUTION UNIT, THE IMPROVEMENT COMPRISING: MEANS IN SAID INSTRUCTION UNIT TO INDICATE THAT AN INSTRUCTION BEING DECODED MAY REQUIRE A DEPARTURE FROM THE NORMAL SEQUENCE OF INSTRUCTIONS; MEANS RESPONSIVE TO SAID INDICATING MEANS TO THEREUPON DETERMINE THE IDENTIFICATION WITHIN SAID STORAGE UNIT OF THE FIRST INSTRUCTION OF THE SEQUENCE TO BE DECODED AND PROCESSED IF A DEPARTURE FROM THE NORMAL SEQUENCE IS REQUIRED; MEANS CONNECTED TO SAID DECODING UNIT TO FURTHER DECODE SAID INSTRUCTION BEING DECODED TO SELECT THE CONDITIONS TO BE TESTED TO DETERMINE IF THE FURTHER INSTRUCTIONS TO BE PROCESSED ARE IN THE NORMAL SEQUENCE OR THE DEPARTURE SEQUENCE; INDICATORS OF SAID CONDITIONS SETTABLE BY SAID EXECUTION UNIT AS A RESULT OF THE EXECUTION OF A PREVIOUSLY DECODED INSTRUCTION; AT LEAST ONE ADDITIONAL DEVICE SETTABLE IN ACCORDANCE WITH THE DATA OF ANY FETCHED INSTRUCTION WORD; MEANS TO INTERRUPT THE PROCESSING OF INSTRUCTIONS OF THE NORMAL SEQUENCE; AND CONTROL MEANS RESPONSIVE TO SAID DECODING MEANS AND TO SAID CONDITION INDICATING MEANS TO ACTIVATE SAID INTERRUPT MEANS AND TO THEN INSTRUCT THE MAIN DATA STORAGE UNIT TO TRANSFER THE IDENTIFIED FIRST INSTRUCTION OF SAID DEPARTURE SEQUENCE TO SAID ADDITIONAL SETTABLE DEVICE FOR IMMEDIATE USE IF THE DEPARTURE SEQUENCE IS TO BE DECODED.