| 摘要 |
PURPOSE:To reduce the capacity of a trace buffer and to attain tracing easily by forming a bit specifying whether an instruction execution address is to be accumulated in a microinstruction as trace information or not and accumulating only the necessary address. CONSTITUTION:A microprogram stored in a control memory 1 is controlled by a control part 6 and a microinstruction in an address specified by an instruction address register 5 is read out and registered in a memory register 2. An instruction decoder 3 decodes the contents of the register 2 to control a register operating part 4 and a controlled hardware 7 (driving device for a magnetic tape or a disk). On the other hand, a trace bit discriminating part 8 discriminates the contents of the register 2, and only when tracing is requied, starts a buffer control part 9, opens a gate 10 to write the contents of an instruction address register 5 in a position specified by a register 12 specified by a trace buffer control part 11 and generate a writing signal 14' to attain writing. Thus, the capacity of the trace buffer can be reduced and tracing can be easily attained. |
