Apple Inc.

Robin D Lash

Erik P Staats

A computer system consists of a plurality of nodes, each with an associated local host, coupled together with a plurality of point-to-point links. An isochronous data channel is established within the computer system between a first subset of the plurality of nodes. The isochronous data channel includes a linked list of buffers which are used as temporary storage locations for data transmitted on the isochronous data channel. Each node which is part of the isochronous data channel is configured as a sender or a receiver and data transmissions are commenced. The presence of isochronous data in the channel generates an interrupt which signals a central processing unit (CPU) that data is available. The data is transferred to an associated location within the linked list of buffers and the CPU then moves on to other tasks. In other embodiments, data is transferred using DMA techniques rather than interrupt driven events. Buffers can also be used to transmit isochronous data.

Isochronous channel having a linked list of buffers

A computer system comprises a plurality of nodes interconnected by point-to-point links and forms a serial bus. Upon system initialization, the bus is scanned and device-specific identification information is retrieved from command and status configuration ROMs associated with each of the plurality of nodes. In one embodiment, a search routine is used to retrieve the device specific information. The search routine begins with the definition of an iterator which is used as a place holder during the search. A simple search begins at the root directory of a hierarchical tree data structure and continues until all directories within the tree have been searched. In more complex embodiments, search relationships (i.e., direction) parameters are defined. Search criteria such as node spec.sub.-- ID and software version numbers are specified and the search is commenced. The search continues until all matching device specific information entries have been returned. The device specific information can be used to load and configure associated drivers for nodes.

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Milpitas, CA, United States of America

Robin D Lash