Abstract: Various embodiments include fault tolerant memory apparatus, methods, and systems, including an apparatus comprising a memory device including a plurality of addressable memory locations, and a memory manager coupled to the memory device, the memory manager including a scheduling unit operable to detect a multi-bit error in data read from the memory device, and to retry the read operation in order to distinguish between an intermittent error and a persistent error.

Abstract: A multiprocessor computer system comprises a dragonfly processor interconnect network that comprises a plurality of processor nodes, a plurality of routers, each router directly coupled to a plurality of terminal nodes, the routers coupled to one another and arranged into a group, and a plurality of groups of routers, such that each group is connected to each other group via at least one direct connection.

Abstract: This document describes, among other things, a computerized system comprising a plurality of processing nodes, a physical channel configured to transfer data between a memory local to a processing node and a network target remote from the processing node, and a block transfer engine configured to allocate a plurality of virtual channels to the physical channel and to transfer a plurality of address-overlapping blocks of data simultaneously using the virtual channels.

Abstract: A high-radix interprocessor communications system and method having a plurality of processor nodes, a plurality of first routers and a plurality of second routers. Each first router is connected to a processor node and to two or more second routers. Each first router includes input ports, output ports, row busses, columns channels and a plurality of subswitches arranged in a n×p matrix. Each row bus receives data from one of the plurality of input ports and distributes the data to two or more of the plurality of subswitches. Each column distributes data from one or more subswitches to one or more output ports. Each row bus includes a route selector, wherein the route selector includes a routing table which selects an output port for each packet and which routes the packet through one of the row busses to the selected output port.

Abstract: Various embodiments include fault tolerant memory apparatus, methods, and systems, including a memory manager for supplying read and write requests to a memory device having a plurality of addressable memory locations. The memory manager includes a plurality of banks. Each bank includes a bank queue for storing read and write requests. The memory manager also includes a request arbiter connected to the plurality of banks. The request arbiter removes read and write requests from the bank queues for presentation to the memory device. The request arbiter includes a read phase of operation and a write phase of operation, wherein the request arbiter preferentially selects read requests for servicing during the read phase of operation and preferentially selects write requests for servicing during the write phase of operation.

Abstract: Various embodiments include an apparatus comprising a memory device including a plurality of addressable memory locations, and a memory manager coupled to the memory device, the memory manager including a scheduling unit and a histogram data structure including a plurality of counters, the scheduling unit operable to detect a single-bit error in data read from the memory device, and to increment a value in a particular one of the plurality of counters, the particular one of the plurality of counters corresponding to the particular bit in the accessed data which incurred the single-bit error in the read data.

Abstract: A multiprocessor computer system comprises a folded butterfly processor interconnect network, the folded butterfly interconnect network comprising a traditional butterfly interconnect network derived from a butterfly network by flattening routers in each row into a single router for each row, and eliminating channels entirely local to the single row.

Abstract: In a system having a N output ports, wherein N is an integer greater than one, a method of distributing packets across the plurality of output ports. A packet having two or more fields is received and a first number is computed as a function of one or more of the plurality of fields. A second number is computed that is modulo base N of the first number and an output port is selected as a function of the second number.

Abstract: A system and method for speculative forwarding of packets received by a router, wherein each packet includes phits and wherein one or more phits include a cyclic redundancy code (CRC). A packet is received and phits of the packet are forwarded to router logic. A cyclic redundancy code for the packet is calculated and compared to the packet's cyclic redundancy code. An error is generated if the cyclic redundancy codes don't match. If the cyclic redundancy codes don't match, a phit of the packet is modified to reflect the error, the CRC is corrected and the corrected CRC is forwarded to the router logic along with the phit reflecting the CRC error. At the router logic, a check is made to see if the packet is still within the router logic. If the packet is still within the router logic and there was a CRC error, the packet is discarded. If, however, the packet is no longer within the router logic and there was a CRC error, the packet is modified so that the next router discards the packet.

Abstract: A multiprocessor computer system comprises a sending processor node and a receiving processor node. The sending processor node is operable to send packets comprising part of a message to a receiver, to maintain a message buffer entry in the sender comprising the sent packets, to track acknowledgment from the receiver that sent packets have been received; to maintain a timer indicating the time since message data has been sent, and to resend packets not acknowledged upon the timer reaching a timeout state. The receiving processor node is operable to send acknowledgement to the sender that received packets have been received, to track packets using a received message table to track which packets comprising part of the message have been received and whether all packets in the message have been received, and to process packets once all packets in a message are received to reassemble the received message.

Abstract: A multiprocessor computer system comprises a sending processor node and a receiving processor node. The sending processor node is operable to send packets comprising part of a message to a receiver, and to send a message complete packet after all packets in the message are sent. The message complete packet includes an indicator of the number of packets in the message, and the message is recognized as complete in the receiver once the number of packets indicated in the message complete packet have been received for the message. The sender tracks acknowledgment from the receiver of receipt of the sent packets; and notifies the receiver when it has received all packets comprising a part of the message.

Abstract: A system and method for routing in a high-radix network. A packet is received and examined to determine if the packet can be routed adaptively. If the packet can be routed adaptively, the packet is routed adaptively, wherein routing adaptively includes selecting a column, computing a column mask, routing the packet to the column; and selecting an output port as a function of the column mask. If the packet can be routed deterministically, routing deterministically, wherein routing deterministically includes accessing a routing table to obtain an output port and routing the packet to the output port from the routing table.

Abstract: A system and method for routing packets from one node to another node in a system having a plurality of nodes connected by a network. A node router is provided in each node, wherein the node router includes a plurality of network ports, including a first and a second network port, wherein each network port includes a communications channel for communicating with one of the other network nodes, a plurality of virtual channel input buffers and a plurality of virtual channel staging buffers, wherein each of the virtual channel staging buffers receives data from one of the plurality of input buffers.