Register substitution during exception processing

Details Register substitution during exception processing Register substitution during exception processing

1992-10-13

1995-01-31

Kriess, Kevin A.

Boots, shoes, and leggings

395725, 364DIG1, 364247, 3642808, 3642632, G06F 1300

Patent

active

053865634

ABSTRACT:
A data processing apparatus and method are described in which a CPU is operable in either a main processing mode (User32) or an exception processing mode (e.g. FIQ32). The CPU has a plurality of main data registers (R0 to R15) and a processing status register (CPSR) for use in the main processing mode. Upon entering the exception processing mode at least one exception data register (R8fiq to R14fiq) is substituted for use in place of a respective corresponding one of the main data registers and the data held within the processing status register is stored within a saved processing status register (SPSRfiq). When the exception processing mode is left, the main data registers are returned for use in place of the exception data registers and the data stored within the saved processing status register is restored to the processing status register. A plurality of exception processing modes are described each having their own associated exception data registers. When a further differing exception occurs within an exception processing mode, the CPU switches to that further differing exception processing mode and uses its own exception data registers and saved processing status register in place of those of the existing processing mode. In this way, nested exception processing is provided.

REFERENCES:
patent: 4217638 (1980-08-01), Namimoto et al.
patent: 4434461 (1984-02-01), Puhl
patent: 4812967 (1989-03-01), Hirosawa et al.
patent: 4905196 (1990-02-01), Kirrman
patent: 4970641 (1990-11-01), Hester et al.
patent: 5095426 (1992-03-01), Senta
patent: 5115506 (1992-05-01), Cohen et al.
patent: 5237700 (1993-08-01), Johnson et al.

Affiliated with

Also associated with

Rating

Register substitution during exception processing does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Register substitution during exception processing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Register substitution during exception processing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1108539