Method and apparatus for local and distributed data memory access (“DMA”) control
First Claim
1. A processor module having a direct memory access (DMA) control apparatus comprising:
- a processor unit for processing data and initiating a generation of one or more local DMA (LDMA) designators upon determining that a portion of the data is unavailable in local memory, and to thereafter continue processing which does not require the unavailable data while waiting for the unavailable data to become available in the local memory;
a LDMA designator holder contained within the processor module and adapted to receive and hold LDMA designator;
a LDMA controller contained within the processor module and communicatively coupled to the LDMA designator holder for receiving the LDMA designator and adapted to carry out a LDMA transaction in accordance with the content of the received LDMA designator to retrieve the unavailable data; and
a plurality of staging registers coupled between the processor unit and the LDMA designator holder, each staging register for storing a different LDMA parameter and for writing a portion of a LDMA designator into a selected portion of the LDMA designator holder;
wherein any one or more of the plurality of staging registers is capable of retaining its stored LDMA parameter between successive writings of LDMA designators to the LDMA designator holder when the LDMA parameter is unchanged so that the one or more staging registers need not be rewritten.
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Accused Products
Abstract
An apparatus for local direct memory access control includes a processor unit for generating a direct memory access designator when needed data is not available and continuing processing which does not require the unavailable data. A memory access designator holder receives the memory access designator, and a local data memory access controller performs a data memory access transaction in accordance with the content of a descriptor. Staging registers hold components of a data memory access designator and transfer the components to a selected portion of the data memory access designator holder. The data memory access controller transfers the contents of the staging registers to the data memory access designator holder when one of the staging registers is written to by the processor unit. The processor unit stalls if a write to the staging register occurs when the data memory access designator holders contain a data memory access designator, and ceases the stall when one of the plurality of data memory access designator holders ceases to contain a data memory access designator.
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Citations
18 Claims
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1. A processor module having a direct memory access (DMA) control apparatus comprising:
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a processor unit for processing data and initiating a generation of one or more local DMA (LDMA) designators upon determining that a portion of the data is unavailable in local memory, and to thereafter continue processing which does not require the unavailable data while waiting for the unavailable data to become available in the local memory; a LDMA designator holder contained within the processor module and adapted to receive and hold LDMA designator; a LDMA controller contained within the processor module and communicatively coupled to the LDMA designator holder for receiving the LDMA designator and adapted to carry out a LDMA transaction in accordance with the content of the received LDMA designator to retrieve the unavailable data; and a plurality of staging registers coupled between the processor unit and the LDMA designator holder, each staging register for storing a different LDMA parameter and for writing a portion of a LDMA designator into a selected portion of the LDMA designator holder; wherein any one or more of the plurality of staging registers is capable of retaining its stored LDMA parameter between successive writings of LDMA designators to the LDMA designator holder when the LDMA parameter is unchanged so that the one or more staging registers need not be rewritten. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A processor module having a direct memory access (DMA) control means comprising:
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a processor means for processing data and initiating a generation of one or more local DMA (LDMA) designators upon determining that a portion of the data is unavailable in local memory, and for continuing processing which does not require the unavailable data while waiting for the unavailable data to become available in the local memory; a LDMA designator holding means contained within the processor means for receiving and holding a LDMA designator; a LDMA controller means within the processor module and communicatively coupled to the LDMA designator holding means for receiving the LDMA designator and for carrying out a LDMA transaction in accordance with the content of the received LDMA designator to retrieve the unavailable data; and a plurality of staging means coupled between the processor means and the LDMA designator holding means, each staging means for storing a different LDMA parameter and for writing a portion of a LDMA designator into a selected portion of the LDMA designator holding means; wherein any one or more of the plurality of staging means is capable of retaining its stored LDMA parameter between successive writings of LDMA designators to the LDMA designator holding means when the LDMA parameter is unchanged so that the one or more staging means need not be rewritten. - View Dependent Claims (10, 11, 12, 13)
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14. A method for providing local direct memory access (DMA) control comprising:
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processing data and initiating a generation of one or more local DMA (LDMA) designators upon determining that a portion of the data is unavailable in local memory, and continuing processing which does not require the unavailable data while waiting for the unavailable data to become available in the local memory; receiving and storing the LDMA designator; carrying out a LDMA transaction in accordance with the content of the received LDMA designator to retrieve the unavailable data; forming each LDMA designator from a plurality of staging registers, each staging register storing a different LDMA parameter and writing a portion of a LDMA designator into a selected portion of the LDMA designator holder; and retaining a value of the LDMA parameter in any one or more of the staging registers between successive writings of LDMA designators when the LDMA parameter is unchanged so the one or more staging registers need not be rewritten. - View Dependent Claims (15, 16, 17, 18)
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Specification