公开(公告)号：JPH1083305A

公开(公告)日：1998-03-31

申请号：JP11344297

申请日：1997-04-14

Applicant: MOTOROLA INC

Inventor： CIRCELLO JOSEPH C ,  GOKINGCO JEFFERSON

IPC: G06F9/42 ,  G06F9/30 ,  G06F9/38 ,  G06F9/46 ,  G06F9/48 ,  G06F11/07

Abstract: PROBLEM TO BE SOLVED: To allow a data processing system to correctly process all the exceptions and to restore a primary state after then by making optional the hardware support for the erroneous matching of an operand. SOLUTION: When a supervisor and hardware support for the erroneous matching of user stack operation are optical, a data processor 3 records stack operation and incorporates a single stack pointer. Since this pointer automatically matches with a 0-modulo-4 address which is lower than present address setting and closet to it, a system error is not generated even without hardware support for the erroneously matching operand. When automatic matching is executed, the data processor 3 stores a format field in an exception stack frame and gives information on a stack pointer at the time of an error. When an exception is processed, the processor 3 restores the stack pointer to the primary value.

公开(公告)号：IE970146A1

公开(公告)日：1997-10-22

申请号：IE970146

申请日：1997-03-03

Applicant: MOTOROLA INC

Inventor： CIRCELLO JOSEPH C ,  GOKINGCO JEFFERSON

IPC: G06F9/42 ,  G06F9/30 ,  G06F9/38 ,  G06F9/46 ,  G06F9/48 ,  G06F11/07 ,  G06F12/00

Abstract: A data processor (3) implements a single system stack pointer (244) to create records of both supervisor and user stack operations when hardware support for misalignment of such stack operations is optional. The single system stack pointer is implemented as a self-aligning stack pointer which automatically aligns itself to a nearest O-modulo-4 address below a current address setting such that no alignment system errors occur even when there is no hardware support for misaligned operands. Once the automatic alignment has occurred, the data processor stores a format field in an exception stack frame to indicate information about the alignment of the stack pointer at the time of the error. When the exception has been serviced, the processor uses the four bit format field stored in the exception stack frame to restore the stack pointer to its original value at the time of the exception.