摘要:
Methods and apparatus provide for interconnecting one or more multiprocessors and one or more external devices through one or more configurable interface circuits, which are adapted for operation in: (i) a first mode to provide a coherent symmetric interface; or (ii) a second mode to provide a non-coherent interface.
摘要:
Disclosed is an apparatus and method for granting guaranteed bandwidth between one or more data transmission priority requesting sources and one or more resources upon request. Data sources that do not request an assigned bandwidth are served on a “best efforts” basis. The system allows additional bandwidth to priority requesting sources when it is determined that the resource and/or the communication path to the resource is under-utilized. The system further allows the granted bandwidth to be shared by more than one source in a multiprocessor system.
摘要:
A method for maintaining cache coherency for a multi-node system using a specialized bridge which allows for fewer forward progress dependencies. A look-up of a local node directory is performed if a request received at a multi-node bridge of the local node is a system request. If a directory entry indicates that data specified in the request has a local owner or local destination, the request is forwarded to the local node. If the local node determines that the request is a local request, a look-up of the local node directory is performed. If the directory entry indicates that data specified in the request has a local owner and local destination, the coherency of the data on the local node is resolved and a transfer of the request data is performed if required. Otherwise, the request is forwarded to all remote nodes in the multi-node system.
摘要:
A method and apparatus are provided for implementing bandwidth control in a communication link. A set link configuration for the communications link establishes a number of clock cycles required to transmit a data envelope. A control function aligns a start of a data packet on a fixed cycle boundary for data envelope transmissions. The control function aligns the start of a data packet in the same byte of the 16 byte field. The control function is implemented with a memory management input/output (MMIO) register and a counter, and allows a transmitting side of the communications link to control the pacing of data packet transmission or bandwidth by aligning all data packets on fixed-cycle boundaries.
摘要:
A method for maintaining cache coherency for a multi-node system using a specialized bridge which allows for fewer forward progress dependencies. A local node makes a determination whether a request is a local or system request. If the request is a local request, a look-up of a directory in the local node is performed. If an entry in the directory of the local node indicates that data in the request does not have a remote owner and that the request does not have a remote destination, the coherency of the data is resolved on the local node, and a transfer of the data specified in the request is performed if required and if the request is a local request. If the entry indicates that the data has a remote owner or that the request has a remote destination, the request is forwarded to all remote nodes in the multi-node system.
摘要:
A method for maintaining cache coherency for a multi-node system using a specialized bridge which allows for fewer forward progress dependencies. A look-up of a local node directory is performed if a request received at a multi-node bridge of the local node is a system request. If a directory entry indicates that data specified in the request has a local owner or local destination, the request is forwarded to the local node. If the local node determines that the request is a local request, a look-up of the local node directory is performed. If the directory entry indicates that data specified in the request has a local owner and local destination, the coherency of the data on the local node is resolved and a transfer of the request data is performed if required. Otherwise, the request is forwarded to all remote nodes in the multi-node system.
摘要:
In a first aspect, a first method of testing a link between a first chip and a second chip is provided. The first method includes the steps of, while operating in a test mode, (1) transmitting test data of sufficient length to enable exercising of worst case transitions from the first chip to the second chip via the link; and (2) performing cyclic redundancy checking (CRC) on the test data to test the link. Numerous other aspects are provided.
摘要:
The present invention provides for an integrated circuit (IC) bus system. A local IC is coupled to a remote IC through a bus interface. A local memory is coupled to the local IC. A bus interface controller is employable to track data transfer requests from the remote IC for data address that are contained within at least one segment of the first partitioned memory range. The bus interface controller is further employable to stop the forwarding of a data transfer request generated within the local IC to the remote IC, if the memory segment count corresponding to the data address of the locally generated data transfer request equals zero.
摘要:
An improved method and apparatus for resource arbitration. Four priority classes, managed high (MH), managed low (ML), opportunistic high (OH) and opportunistic low (OL), are defined. A priority class is assigned to each resource access request. An access request concentrator (ARC) is created for each resource, through which the resource is accessed. An access request is chosen at each ARC using the priority order MH, ML, OH, and OL, in decreasing order of priority. If OH priority class resource access requests are locked out, the priority order is temporarily changed to OH, OL, MH, and ML, in decreasing order of priority. If OL priority class resource access requests are locked out, the priority order is temporarily changed to MH, OL, OH, and ML, in decreasing order of priority.
摘要:
A method of providing maintenance for a memory device of a computer system without interrupting operation of the computer system, by partially mirroring a primary memory array in a secondary memory array, wherein the secondary memory array has a different amount of available memory than the primary memory array. Values are copied from the primary memory array to the permanent storage device, allowing the primary memory array to quiesce and be serviced while using the secondary memory array to operate the computer system. Thereafter, the primary memory array is brought on-line, and the mirrored values are written back from the secondary memory array to the primary memory array. The memory service program itself may be embedded in the operating system. In an illustrative embodiment, the primary memory array is located on a first removable memory card, and the secondary memory array is located on a second removable memory card. The amount of memory available in the secondary memory array may be programmable.