Abstract: A mechanism provides for sending an envelope and replying to an envelope. A transmitter is configured to send an envelope. A receiver is coupled to the transmitter, wherein the receiver is configured to receive the envelope and generate a reply envelope. A send buffer is coupled to the transmitter. A receive buffer is coupled to the receiver. A retry timer is coupled to the transmitter, wherein the retry timer is configured to reset upon the receipt of a reply envelope correlated to the transmit envelope. The transmitter is configured to retransmit an envelope if the transmitter does not receive a corresponding reply envelope within a selected time period as determined by the retry timer. This leads to a decrease in the total number of envelopes, transmitted from both the transmitter and the receiver.

Abstract: A method and apparatus are provided for implementing enhanced vertical ECC storage in a dynamic random access memory. A dynamic random access memory (DRAM) is split into a plurality of groups. Each group resides inside a DRAM row address strobe (RAS) page so that multiple locations inside a group can be accessed without incurring an additional RAS access penalty. Each group is logically split into a plurality of segments for storing data with at least one segment for storing ECC for the data segments. For a write operation, data are written in a data segment and then ECC for the data are written in an ECC segment. For a read operation, ECC are read from an ECC segment, then data are read from the data segment.

Abstract: A method and calibration apparatus implement calibration of sampling of a data strobe signal (DQS) during synchronous dynamic random access memory (DRAM) reads. A calibration control is provided to enable calibration testing. A selected one of a received DQS signal and an internal Enable signal is driven onto a data mask (DQM) IO during a DRAM read for calibration testing. The received DQS signal and the internal Enable signal are used to adjust the Enable delay to generally center the preamble time at the DQS receiver.

Abstract: A method, apparatus, system, and signal-bearing medium that in an embodiment determine whether a current number of buffers allocated to a queue pair is less than a maximum number of buffers for the queue pair, decide whether a current number of buffers allocated to an operation type is less than a maximum number of buffers for the operation, and allocate a buffer to the queue pair if the queue pair requests the buffer for an operation having the operation type and the determining and the deciding are true. In this way, too much buffer space is prevented from being assigned to particular operation and to a particular queue pair.

Abstract: A method and calibration apparatus implement calibration of sampling of a data strobe signal (DQS) during synchronous dynamic random access memory (DRAM) reads. A calibration control is provided to enable calibration testing. A selected one of a received DQS signal and an internal Enable signal is driven onto a data mask (DQM) IO during a DRAM read for calibration testing. The received DQS signal and the internal Enable signal are used to adjust the Enable delay to generally center the preamble time at the DQS receiver.

Abstract: A method and apparatus are provided for implementing enhanced vertical ECC storage in a dynamic random access memory. A dynamic random access memory (DRAM) is split into a plurality of groups. Each group resides inside a DRAM row address strobe (RAS) page so that multiple locations inside a group can be accessed without incurring an additional RAS access penalty. Each group is logically split into a plurality of segments for storing data with at least one segment for storing ECC for the data segments. For a write operation, data are written in a data segment and then ECC for the data are written in an ECC segment. For a read operation, ECC are read from an ECC segment, then data are read from the data segment.

Abstract: A method and apparatus are provided for implementing enhanced vertical ECC storage in a dynamic random access memory. A dynamic random access memory (DRAM) is split into a plurality of groups. Each group resides inside a DRAM row address strobe (RAS) page so that multiple locations inside a group can be accessed without incurring an additional RAS access penalty. Each group is logically split into a plurality of segments for storing data with at least one segment for storing ECC for the data segments. For a write operation, data are written in a data segment and then ECC for the data are written in an ECC segment. For a read operation, ECC are read from an ECC segment, then data are read from the data segment.

Abstract: A method and calibration apparatus implement calibration of sampling of a data strobe signal (DQS) during synchronous dynamic random access memory (DRAM) reads. A calibration control is provided to enable calibration testing. A selected one of a received DQS signal and an internal Enable signal is driven onto a data mask (DQM) IO during a DRAM read for calibration testing. The received DQS signal and the internal Enable signal are used to adjust the Enable delay to generally center the preamble time at the DQS receiver.

Abstract: A method and calibration apparatus implement calibration of sampling of a data strobe signal (DQS) during synchronous dynamic random access memory (DRAM) reads. A calibration control is provided to enable calibration testing. A selected one of a received DQS signal and an internal Enable signal is driven onto a data mask (DQM) 10 during a DRAM read for calibration testing. The received DQS signal and the internal Enable signal are used to adjust the Enable delay to generally center the preamble time at the DQS receiver.

Abstract: A method, apparatus and computer program product are provided for implementing queue pair connection protection over an interconnect network, such as InfiniBand. A message packet is received for a queue pair (QP) and the QP is checked for an imminent connection failure. Responsive to identifying an imminent connection failure, a special message processing mode is established for the QP. After the special message processing mode is established, packets of the message are received without establishing a message queue entry and without storing packet data.

Abstract: A method, apparatus, and computer program product are provided for implementing a receive function over an interconnect network, such as InfiniBand. A virtual lane (VL) with a pending packet for a queue pair (QP) is selected. Then the pending packet is checked for an exceptional condition. Responsive to identifying the exceptional condition for the pending packet, a state bit is set for freezing the selected VL; and an interrupt is generated to firmware. Responsive to receiving the interrupt, the firmware determines a cause for freezing the selected VL and performs a responsive action. For example, the responsive action performed by firmware includes firmware performing an error recovery procedure (ERP) for the QP; firmware updating a state for the QP; or firmware performing application unique processing for the QP.

Abstract: A method, apparatus, and computer program product are provided for implementing global to local queue pair translation in a network transport layer. A global queue pair number is identified. The global queue pair number is translated to a smaller local queue pair number. The local queue pair number is used for storing local queue pair context data for outbound header generation and inbound header checking. Upper layers of the network protocol above the network transport layer are allowed to use the global queue pair numbers.

Abstract: A receiver for an InfiniBand network contains a buffer and a control memory. A set of pointers for receive queues in the buffer is maintained in the control memory. Two independent queues exist for incoming messages from a given source, one for writes and the other for reads. The receiver controls the various queue pointers to generate appropriate acknowledgments and negative acknowledgment messages, and to transfer data as required to and from the host over an internal bus. Preferably, the receiver delays acknowledging certain write requests if requests are pending on the read queue. Preferably, the control memory and the major control functions of the receiver are implemented in hardware on a ASIC chip.

Abstract: A method, apparatus and computer program product are provided for implementing a transmit queue. A queue pair context memory is provided for storing a set of pointers for each queue pair. The set of pointers are used to control the transmit queue for receiving, processing, and sending messages. Responsive to identifying an error for a queue pair, a limit pointer enable bit and a limit pointer to identify a last request for processing after the error are stored in the queue pair context memory for the queue pair.

Abstract: A method, apparatus, and computer program product are provided for implementing a receive function over an interconnect network, such as InfiniBand. A virtual lane (VL) with a pending packet for a queue pair (QP) is selected. Then the pending packet is checked for an exceptional condition. Responsive to identifying the exceptional condition for the pending packet, a state bit is set for freezing the selected VL; and an interrupt is generated to firmware. Responsive to receiving the interrupt, the firmware determines a cause for freezing the selected VL and performs a responsive action. For example, the responsive action performed by firmware includes firmware performing an error recovery procedure (ERP) for the QP; firmware updating a state for the QP; or firmware performing application unique processing for the QP.

Abstract: A method, apparatus and computer program product are provided for implementing queue pair connection protection over an interconnect network, such as InfiniBand. A message packet is received for a queue pair (QP) and the QP is checked for an imminent connection failure. Responsive to identifying an imminent connection failure, a special message processing mode is established for the QP. After the special message processing mode is established, packets of the message are received without establishing a message queue entry and without storing packet data.

Abstract: A receiver for an InfiniBand network contains a buffer and a control memory. A set of pointers for receive queues in the buffer is maintained in the control memory. Two independent queues exist for incoming messages from a given source, one for writes and the other for reads. The receiver controls the various queue pointers to generate appropriate acknowledgments and negative acknowledgment messages, and to transfer data as required to and from the host over an internal bus. Preferably, the receiver delays acknowledging certain write requests if requests are pending on the read queue. Preferably, the control memory and the major control functions of the receiver are implemented in hardware on a ASIC chip.

Abstract: A method, apparatus, and computer program product are provided for implementing global to local queue pair translation in a network transport layer. A global queue pair number is identified. The global queue pair number is translated to a smaller local queue pair number. The local queue pair number is used for storing local queue pair context data for outbound header generation and inbound header checking. Upper layers of the network protocol above the network transport layer are allowed to use the global queue pair numbers.

Abstract: A method, apparatus and computer program product are provided for implementing a transmit queue. A queue pair context memory is provided for storing a set of pointers for each queue pair. The set of pointers are used to control the transmit queue for receiving, processing, and sending messages. Responsive to identifying an error for a queue pair, a limit pointer enable bit and a limit pointer to identify a last request for processing after the error are stored in the queue pair context memory for the queue pair.

Abstract: Embodiments are provided in which a method for delaying a strobe signal for a first pre-specified amount of time is described. A test signal is sent through a first number of delay books and a test is done as to whether it takes the test signal approximately a second pre-specified amount of time to pass the first number of delay books. Then, the number of delay books is increased or decreased by one at a time and until the number of delay books reaches a second number where it takes the test signal approximately the second pre-specified amount of time to pass the second number of delay books. From the second number, a third number of delay books is determined which is needed to cause a propagation delay approximately equal to the first pre-specified amount of time. Finally, the strobe signal is passed through the third number of delay books.