公开(公告)号：GB1202489A

公开(公告)日：1970-08-19

申请号：GB6055668

申请日：1968-12-20

Applicant: IBM

Inventor： ATTWOOD DENNIS PATON ,  SYME DAVID MCCULLOCH ,  TUFFILL HAROLD WILLIAM

IPC: G06F9/22 ,  G06F9/30 ,  G06F11/22 ,  G06F11/267

Abstract: 1,202,489. Data processing. INTERNATIONAL BUSINESS MACHINES CORP. 20 Dec., 1968, No. 60556/68. Heading G4A. In a microprogrammed data processing system, simulated monitoring or control data is forced from an injection register into bit storage positions of data processing circuitry on identification of a predetermined stage in the execution of a microprogramme, thereby to initiate a system test or response other than by means of the microprogramme. Injection may occur when a preset counter, counted down as the microprogramme proceeds, reaches zero, or when a counter incremented from zero reaches a prespecified value, or when the current address supplied to a microprogramme read-only store reaches a prespecified value. A presettable mask may be used to prevent some portions of the injection register being used. A plurality of injection registers may be used at different points in the microprogramme. Retry means, normally used for retrying a macroinstruction during which an error occurred, using saved system states, may be tested by the above means by forcing simulated error indicating information in the above way. A "diagnose" macroinstruction is used to load the injection register and the means specifying the desired stage in the microprogramme from main memory, or the injection register may be loaded from a keyboard. The microprogrammes could be stored in the main memory. The bit storage positions which are forced may relate to occurrence of a parity error or availability of a peripheral unit or microprogrammo branch.