METHOD FOR SETTING CONDITION AND CONDUCTING TEST BY SPECIAL MILLICODE INSTRUCTION

摘要

PROBLEM TO BE SOLVED: To reduce the number of millicode instructions and the number of machine cycles by generating a necessary value through the use of information in a general-purpose register, a condition code and a millicode flag. SOLUTION: A cache memory unit 12 logically contains a writable inner code array 13 where a continuous address can be designated and millimode routines which are frequently called are stored in the inner code array 13. When a system enters a millimode millicode routine, one or plural conversion fetch (TPFET) millicode instruction supports a conversion/test (TRT) instruction. The TRFET instruction follows an ESA/390 architecture and generates the necessary value by using information in a general-purpose register, a condition code and a millicode flag. Thus, the general-purpose registers 1 of the processor and the condition code are updated.