24/06/2005 - Controller General of Patents, Designs, and Trade Marks

(21) Application No. 2577/DEL/1997 A (22) Date of filing of Application: 11/09/1997
(54) Title of the invention: “A DATA PROCESSING APPARATUS AND A METHOD OF
OPERATING THE SAME.”
(51) International Classification 7 : G 06F 9/34, G 06F 12/02
(30) Priority Data :
(31) Document No.: NA
(32) Date : NA
(33) Name of convention country :
NA
(66) Filed U/s 5(2) : NIL
(61) Patent of addition to application No. : NA
(62) Filed on : NA
(63) Divisional to Application No. :NIL
(64) Filed on : NA
Total No. of Pages:119
(57) Abstract:
(71) Name of the applicant:
ARM LIMITED.
Address of the Applicant:
110 Fulbourn Road, Cherry
Hinton, Cambridge CB1 9NJ,
England.
(72) Name of the Inventor:
RICHARD YORK
HEDLEY JAMES FRANCES
DOMINIC SYMES
STUART BILES
The present invention provides a data processing apparatus comprising: a plurality of registers for
storing data items to be processed; a processor for processing instructions to be applied to data items
stored in said plurality of registers; and register remapping logic for converting a logical register
reference within a preselected set of instructions to a physical register reference identifying the register
containing the data item required for processing by the processor.
By this approach, a remapping instruction need only by executed once in order for the remapping to be
applied to a desired number of instructions. This is in contrast to prior art techniques, where subsequent
to a remapping instruction being executed, the remapping is applied to all subsequent instructions, ie. a
desired number of instructions cannot be selected.
The invention is particularly advantageously employed in apparatus arranged to repeat in instruction
loop, the instruction loop including said preselected set of instructions . In such cases, loop hardware
used to manage the repeat instruction can be arranged to update the register remapping locig each time
the instruction loop is repeated, and hence the remapping logic is only executed once prior to the repeat
instruction being executed.
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