公开(公告)号：CA1215783A

公开(公告)日：1986-12-23

申请号：CA464281

申请日：1984-09-28

Applicant: TANDEM COMPUTERS INC

Inventor： HORST ROBERT W ,  LYNCH SHANNON J ,  COSTANTINO CIRILLO L ,  BEIRNE JOHN M

IPC: G06F7/00 ,  G06F9/30 ,  G06F9/38 ,  G06F13/38

Abstract: The various functional units which comprise a central processing unit of a computer are organized so as to enable a main arithmetic logic unit and special function units including an auxilliary arithmetic logic unit to access data registers, literal constants, and data from a memory cache. A general purpose bus closely couples the functional units to the main data paths and allows the CPU sequencer to branch on numerous conditions which may be indicated via test lines. Parity from the functional units is sent a clock cycle later than results in order that the parity path does not affect machine cycle time. The architecture allows unused microcode options to be used to check for correct CPU operation by halting CPU operation on a miscompare of two buses.