Abstract:
A system and method for tracking responses to InfiniBand RDMA Reads. When an RDMA Read or Read request is issued by a transmit module, a receive module is informed of the packet sequence numbers (PSN) associated with the expected RDMA Read responses. The receive module maintains a linked list for each queue pair that issues RDMA Reads. Each entry in the linked list corresponds to one RDMA Read for the associated queue pair, and identifies the first and last PSN and includes a link to the next entry in the linked list. When the final RDMA Read response is received, the receive module notifies the transmit module, which can then retire the RDMA Read from its retry queue.
Abstract:
A system and method for shared buffering of InfiniBand virtual lanes and queue pairs. Instead of allocating dedicated memory space (e.g., a set of FIFO queues), a shared memory dynamically accommodates traffic received on different virtual lanes and/or queue pairs of an InfiniBand network. A multi-port RAM comprises memory buckets or elements for storing contents of InfiniBand packets. For each queue pair and/or virtual lane, matching head and tail pointers identify the first and last elements of a linked list of traffic buffered from that queue pair or virtual lane. A multi-port control structure mirrors the RAM. For each node in a queue pair or virtual lane's linked list, a corresponding entry in the control structure relates to the corresponding memory element and stores an identifier of the memory element and control entry corresponding to the next node in the linked list.
Abstract:
An apparatus and method for enabling hot swapped circuit boards to receive multiple power voltages from a backplane and supply the multiple power voltages to devices on the circuit board in a predictable sequence. An apparatus according to the invention would include a circuit board having an electrical connector, a sequencing circuit, and an element. The electrical connector of the circuit board receives the multiple power voltages from another circuit board, such as a backplane or motherboard. The sequencing circuit receives the multiple power voltages from the electrical connector. When a part of the sequencing circuit receives a signal indicating that the sequencing circuit has received a first power voltage, the sequencing circuit provides a second power voltage to the element electrically coupled to the sequencing circuit.
Abstract:
A printing method includes applying at least one of a plurality of pigmented colored inks to a receiving surface. A colorless ink is applied to the receiving surface. A majority of the colorless ink is ejected from of first nozzles on a printhead used for ejecting the colorless ink. At least 30% of an area on the receiving surface, which is passed over by the first nozzles, is covered with the colorless ink during a single pass of the printhead over the area.
Abstract:
A system and method for processing interleaved Sends of encapsulated communications and responses to RDMA Reads in a single InfiniBand queue pair receive queue. The queue is implemented as one or more linked lists of memory buckets, and stores Send commands (containing encapsulated communications or RDMA Read descriptors for retrieving a communication) until their associated communications are assembled and forwarded to a transmit module. The queue grows as new InfiniBand packets are received, and shrinks as communications (e.g., Ethernet packets) are forwarded. A next packet pointer identifies the next Send command whose communication should be assembled. If it is an encapsulated communication, the communication is forwarded. Otherwise, RDMA Read requests are issued and the responses bypass the tail of the queue and are assembled in an assembly area at the head of the queue.
Abstract:
A system and method for implementing flow control, at the link and/or transport layers, for InfiniBand receive traffic. A shared memory structure may be used for combined queuing of virtual lane and queue pair traffic. Each virtual lane is allocated a number of memory buffers; a packet is dropped if buffering it would cause its virtual lane to exceed its allocation of buffers. For each active queue pair, a linked list of buffers is maintained in the structure. Each queue pair is dedicated zero or more of its virtual lane's buffers, and may also use a set of buffers shared among multiple queue pairs. Thresholds are established in a queue pair's dedicated set of buffers and/or the shared set of buffers. As each threshold number of buffers is used, a queue pair can advertise fewer message credits. RNR-NAKs are issued when no more buffers are available to a queue pair.
Abstract:
A system and a method for improving printing performance are provided. One method of improving printing performance performing a first print operation utilizing a printhead comprising a plurality of resistors by ejecting ink from a plurality of chambers each associated with at least one of at least some of the plurality of resistors, selectively energizing at least some of the plurality of resistors at an energy level insufficient to eject ink from the plurality of chambers, and performing a second print operation utilizing the printhead.
Abstract:
A method and apparatus for placing fluid droplets onto a surface in which at least one of a group of nozzles is substantially aligned with a first of parallel line segments on the surface moving in a first direction relative to the nozzles; at least one droplet is ejected from the first nozzle onto a target on the first segment; the group of nozzles is moved in a second direction having a component orthogonal to the first direction to respectively align first and second nozzles in the group with a second segment and with the first segment; the and fluid droplets are ejected from the nozzles onto targets on the segments, the center to center spacing of the targets along the segments equaling one or a multiple of the center to center spacing of the nozzles orthogonal to the segments.
Abstract:
An apparatus and method for comparing identifications of circuit boards in a midplane. When a first circuit board and a second circuit board are inserted into opposite sides of the midplane, an incompatibility between the first circuit board and the second circuit board may damage or impair the operation of one or both of the first circuit board and the second circuit board. To solve this problem, a first identification is stored on the first circuit board and a second identification is stored on the second circuit board. If the first identification of the first circuit board and the second identification of the second circuit board indicate an incompatibility, then one or both of the first circuit board and the second circuit board is/are prevented from fully powering up.
Abstract:
A printing method includes applying at least one of a plurality of pigmented colored inks to a receiving surface. A colorless ink is applied to the receiving surface. A majority of the colorless ink is ejected from of first nozzles on a printhead used for ejecting the colorless ink. At least 30% of an area on the receiving surface, which is passed over by the first nozzles, is covered with the colorless ink during a single pass of the printhead over the area.