公开(公告)号：DE2363100A1

公开(公告)日：1974-07-11

申请号：DE2363100

申请日：1973-12-19

Applicant: IBM

Inventor： ENGER THOMAS ARTHUR ,  EVANS JUN CHARLES WESLEY ,  JOHNSON LANCE HERMAN

IPC: G06F9/28 ,  G06F9/22 ,  G06F9/26 ,  G06F9/10 ,  G06F15/48 ,  G05B15/02

Abstract: A microprogram control subsystem discloses two control stores, one of which is accessed and utilized only on the first cycle of a microprogram sequence utilized to execute an information handling system instruction. A portion of the operation code of the system instruction is used to address the first-cycle control store to provide access to a microinstruction having fewer binary bits than normal microinstructions, and is effective to direct access to the remainder of the microprogram sequence contained in the other control store.