公开(公告)号：DE1499722B1

公开(公告)日：1972-05-25

申请号：DE1499722

申请日：1966-10-11

Applicant: IBM DEUTSCHLAND

Inventor： HOWARD OTTAWAY GERALD ,  PAINKE HELMUT ,  RAGLAND THOMAS ,  SCHELER TITUS ,  WILL HELMUT ,  VAUGHN WRIGHT WILLIAM

IPC: G06F9/26 ,  G06F9/20

Abstract: 1,107,486. Microprogramming. INTERNATIONAL BUSINESS MACHINES CORPORATION. 25 Aug., 1966 [22 Oct., 1965], No. 38140/66. Heading G4A. Bits from a stored word are subjected to a variable logical operation to get the address of the next word. An address applied to a computer microprogramme read-only store controls three decoders. The first two decoders select a word location in the store and the third decoder selects and passes to a register one of three portions of the word as the next micro-instruction. Either of two of the portions fills the register but the third leaves a part of the register unchanged. The next store address is obtained from sections of said register, said " part " of the register feeding the second decoder, another part feeding the third decoder, and a third part being applied to the first decoder via a " use " circuit which either passes the third part unchanged, or AND's or OR's or EXCL-OR's the bits of the third part with corresponding bits from one of a number of working registers in the computer. What the " use " circuit does to the third part is controlled by other bits from the current microinstruction.