| 摘要 |
PURPOSE:To improve the reliability of a data processor by retrying an instruction even after contents of a main storage are rewritten by a move instruction if three specific conditions are satisfied. CONSTITUTION:Not the hardware error where retry is impossible but the error that information or the like essential for instruction retry other than contents of the main storage is not rewritten is decided, it is checked whether contents of the main storage are rewritten or not. If they are rewritten, it is checked whether a flip flop FF 105, an FF 121, and an FF 127 are '1' or not. If they are '1', that is, it is decided that the move instruction is executed and contents of the first main storage operand are not rewritten by execution of the move instruction and contents of the main storage area of the move instruction word itself are not rewritten by execution of the move instruction, the instruction word is taken out again on a basis of the current instruction address in a register 122 to retry the execution of the instruction. |
