| 摘要 |
PURPOSE:To read following instructions in succession to a readout of an instruction at a branch destination by adding an adding function for instruction readout width to an adder which is used to calculate a branch destination address. CONSTITUTION:A branch instruction is inputted to an instruction register 4 and the value of its displacement field is selected by selectors 16 and 17 and inputted to the adder 5. Consequently, the address of the branch destination is calculated and inputted to a register 6. The branch destination address inputted to the circuit 6 is transferred to a storage device 1 to read the 1st instruction at the branch destination and the address calculated by adding eight bytes as instruction readout width to the branch destination address is held in the register 6. Then, the 2nd instruction at the branch destination is read out by said address. Further, the adder 8 adds readout with corresponding to two instructions at the branch destination to read the 3rd instruction. Similarly, said operation is repeated to generate readout addresses successively by the adder 8, and read-out of the instructions excecutes successively.
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