| 摘要 |
PURPOSE:To shorten a time required for generating a nullifying signal, by nullifying an output of a microinstruction based on an output of an error detection signal input means for displaying a 1 bit error or a 2 bit error, when it has occurred. CONSTITUTION:A mu-instruction is read out together with a check bit from a memory for a micro mu program PG, and is checked, and as a result, when one of syndrome SD constitution bits S0-S5 becomes ''1'', a nullifying signal INVLD is supplied to a mu-instruction decoded destination through an OR circuit 1. In case when an error is 1 bit error, after the nullifying signal has been generated, the SD constitution bit S6 becomes ''1'', and a correct timing signal CSCRT for correcting the mu-instruction is generated from an FF5 through an AND circuit 3. When the bit S6 becomes ''1'', a signal CSSGL for informing the existence of the 1 bit error is generated to an output of the memory for the muPG from an FF6. In case when an output of the circuit 1 is ''1'' and the bit S6 is ''0'', a signal CSDBLE for informing the existence of the 2 bit error is generated to an output of the memory for the muPG from an FF7 through an AND circuit 4. |
