JPS5757349A - Microprogram control type data processor - Google Patents

Abstract

PURPOSE:To obtain a data processor having a history recording function with extending and flexible properties, by recording the addresses of a microinstruction existing before and after the address of a microprogram only when this address has a discontinuous change. CONSTITUTION:The micro (mu) instrution which is read to a main storage device 1 by a address designated by a mu instruction address register (AR) 2 is stored in an instrution register 7 and executed by an instruction execution controlling part 8. The contents of the AR2 are compared with the contents of mu instruction AR3 which is precedent to the AR2 by instruction and already executed through a detecting circuit 4. When the difference of these two contents is not equal to a prescribed value, the contents of the AR2 are shunted to a mu instruction address shunting register 15. Then an address discontinuous change signal is produced from the circut 4 to be supplied to an interruption supply circuit 6 via a gate 5 in the form of an interruption signal. The output of an interruption control circuit 9 which is set and reset is applied to the gate 5 from the part 8 to control the permission/inhibition for the interruption of the circuit 6. The circuit 6 gives an input to the AR2 to produce an interruption and then inhibits the interruption of the circuit 9 to start the recording of history.