Abstract: A plurality of registers implemented in association with a memory physical layer interface (PHY) can be used to store one or more instruction words that indicate one or more commands and one or more delays. A training engine implemented in the memory PHY can generate at-speed programmable sequences of commands for delivery to an external memory and to delay the commands based on the one or more delays. The at-speed programmable sequences of commands can be generated based on the one or more instruction words.

Abstract: A controller integrated in a memory physical layer interface (PHY) can be used to control training used to configure the memory PHY for communication with an associated external memory such as a dynamic random access memory (DRAM), thereby removing the need to provide training sequences over a data pipeline between a BIOS and the memory PHY. For example, a controller integrated in the memory PHY can control read training and write training of the memory PHY for communication with the external memory based on a training algorithm. The training algorithm may be a seedless training algorithm that converges on a solution for a timing delay and a voltage offset between the memory PHY and the external memory without receiving, from a basic input/output system (BIOS), seed information that characterizes a signal path traversed by training sequences or commands generated by the training algorithm.

Abstract: A plurality of registers implemented in association with a memory physical layer interface (PHY) can be used to store one or more instruction words that indicate one or more commands and one or more delays. A training engine implemented in the memory PHY can generate at-speed programmable sequences of commands for delivery to an external memory and to delay the commands based on the one or more delays. The at-speed programmable sequences of commands can be generated based on the one or more instruction words.

Abstract: A controller integrated in a memory physical layer interface (PHY) can be used to control training used to configure the memory PHY for communication with an associated external memory such as a dynamic random access memory (DRAM), thereby removing the need to provide training sequences over a data pipeline between a BIOS and the memory PHY. For example, a controller integrated in the memory PHY can control read training and write training of the memory PHY for communication with the external memory based on a training algorithm. The training algorithm may be a seedless training algorithm that converges on a solution for a timing delay and a voltage offset between the memory PHY and the external memory without receiving, from a basic input/output system (BIOS), seed information that characterizes a signal path traversed by training sequences or commands generated by the training algorithm.

Abstract: Various method and apparatus embodiments for training a delay for enabling a data strobe signal in a memory subsystem are disclosed. In one embodiment, a system includes a memory controller configured to receive a data strobe signal. The memory controller includes a training circuit. The training circuit includes a first storage circuit coupled to receive the data strobe signal on a data input and an enable signal on a clock input, and a training unit configured to, based on an output signal received from the first flip-flop, adjust a phase of the enable signal until an assertion of the enable signal coincides with a preamble indication in the data strobe signal.

Abstract: Various method and apparatus embodiments for training a delay for enabling a data strobe signal in a memory subsystem are disclosed. In one embodiment, a system includes a memory controller configured to receive a data strobe signal. The memory controller includes a training circuit. The training circuit includes a first storage circuit coupled to receive the data strobe signal on a data input and an enable signal on a clock input, and a training unit configured to, based on an output signal received from the first flip-flop, adjust a phase of the enable signal until an assertion of the enable signal coincides with a preamble indication in the data strobe signal.

Abstract: A pseudo random bit stream generator is disclosed which has a fully programmable pseudo random polynomial up to the supported width of the CSRs, fully programmable tap selection for providing any specified combination of generator state taps, and fully programmable parallel sequence generation which determines the number of sequential bits calculated and how much the sequence generator advances per clock.

Abstract: A pseudo random bit stream generator is disclosed which has a fully programmable pseudo random polynomial up to the supported width of the CSRs, fully programmable tap selection for providing any specified combination of generator state taps, and fully programmable parallel sequence generation which determines the number of sequential bits calculated and how much the sequence generator advances per clock.

Abstract: An apparatus includes a plurality of data lines defining a data bus for communicating data. A controller is operable to communicate a plurality of data transfers over the data bus using a plurality of data time slots, wherein for at least a subset of the data time slots the controller is operable to communicate an associated data bus inversion indicator indicating that bits communicated during the associated data time slot are inverted, the data bus inversion indicators for the subset of the data transfers are grouped into a data bus inversion vector, and the controller is operable to communicate a global data bus inversion indicator indicating an inversion of the data bus inversion vector.

Abstract: A method for controlling sharing of resources in a multi-threaded environment includes entering a finite state machine state sequence; controlling resource-sharing threads using the finite state machine state sequence; and exiting the finite state machine state sequence when shared resource control is complete. A multi-threaded shared resource control system includes a finite state machine configured to control multi-threaded access to shared resources; a plurality of producer threads regulated by the finite state machine; and a plurality of consumer threads regulated by the finite state machine.

Abstract: An apparatus includes a plurality of data lines defining a data bus for communicating data. A controller is operable to communicate a plurality of data transfers over the data bus using a plurality of data time slots, wherein for at least a subset of the data time slots the controller is operable to communicate an associated data bus inversion indicator indicating that bits communicated during the associated data time slot are inverted, the data bus inversion indicators for the subset of the data transfers are grouped into a data bus inversion vector, and the controller is operable to communicate a global data bus inversion indicator indicating an inversion of the data bus inversion vector.

Abstract: An apparatus for linking a hot-plug device to a host includes a slave interface circuit for connection to the host; a master interface circuit for connection to the hot-plug device; and direction, data, and clock lines that link the master and slave interface circuits. A control logic circuit detects a Presence Detect signal on the direction line. A method of determining a connection between a host and a hot-plug device includes asserting a direction signal on a direction line to control a direction of a flow of data between the host and the hot-plug device; toggling the direction signal to indicate a presence of the hot-plug device; and indicating a disconnect after a given period of inactivity in the toggling. A method of linking a host and a hot-plug device interface circuit for connection to a hot-plug device includes asserting a Presence Detect signal on the direction line.

Abstract: An apparatus for linking a hot-plug device to a host includes a slave interface circuit for connection to the host; a master interface circuit for connection to the hot-plug device; and direction, data, and clock lines that link the master and slave interface circuits. A control logic circuit detects a Presence Detect signal on the direction line. A method of determining a connection between a host and a hot-plug device includes asserting a direction signal on a direction line to control a direction of a flow of data between the host and the hot-plug device; toggling the direction signal to indicate a presence of the hot-plug device; and indicating a disconnect after a given period of inactivity in the toggling. A method of linking a host and a hot-plug device interface circuit for connection to a hot-plug device includes asserting a Presence Detect signal on the direction line.

Abstract: A method for controlling hot-plug behavior includes identifying a hot-plug event caused by a hot-plug device; generating hot-plug threads that execute a hot-plug operation; executing a finite state machine state sequence to regulate hot-plug threads involved in the hot-plug operation; and completing the hot-plug operation at the end of the finite state machine state sequence. A computer usable medium has computer readable program code embodied therein for causing a computer system to execute the method for controlling hot-plug behavior. A hot-plug control system for a computer system includes a hot-plug device; a set of hot-plug threads that regulate operations in the hot-plug device; and a finite state machine that controls execution of instructions using the set of threads.

Abstract: A system for permitting remote user access to regions of memory that have been exported for remote direct memory access purposes. The system supports dynamically changing access privileges to remote users without requiring intervention from an operating system. The system may include a memory region table and a memory window table for supporting address translations. Entries in the memory window table may include a region remote access key and a window remote access key. The memory region table may include fields for a physical address, an access value, a protection domain value, and a length of memory region.

Abstract: A method for transmitting messages between two processes includes creating a communications channel between a first channel adapter coupled to a client process and a second channel adapter coupled to a remote process. The method further includes reading a request message at the first channel adapter, segmenting the request message into a series of packets, assigning a sequence number to each packet, and transmitting the packets in order to the second channel adapter through the communications channel. The method further includes receiving the packets at the second channel adapter and sending at least one acknowledgement message to the first channel adapter in response to the received packets.

Abstract: A system for permitting remote user access to regions of memory that have been exported for remote direct memory access purposes is provided. The system supports dynamically changing access privileges to remote users without requiring intervention from an operating system.

Abstract: The present invention is directed to a system having a shared processing resource, a plurality of processing modules and a synchronization control module. The shared processing resource is configured to perform processing operations in connection with input data provided by the processing modules, in response to a start indication. Each of the processing modules is configured to perform selected processing operations. At least one of the processing modules is configured to provide input data to the shared processing resource. Each processing module that provides input data is configured to generate a hold indication and to provide the input data to the shared processing resource in response to a synchronization barrier lock. Each processing module is configured to generate a start enable indication. Each processing module that provides input data generates a start enable indication after providing the input data.

Abstract: A system and method for circuitry design verification testing using a structure of interface independent classes to provide for rapid prototyping and design modification while maximizing test code re-use. A circuit simulation subsystem is interfaced with a test subsystem. The test subsystem employs a system transaction class for collecting common routines and pointers to device transactions. One or more configuration transaction classes derived from the system transaction class define transactions between functional models within the simulation subsystem and cause instantiation of the respective functional models. Operations are performed on the functional models via pointers to interface independent transaction classes which define interfaces to the devices. The operations are mapped to the current designs of the functional models by subclasses of the interface independent transaction classes.

Abstract: A system and method for circuitry design verification testing which provides for maximized code re-use without unnecessary allocation of system resources. A circuit simulation subsystem is interfaced with a test subsystem. The test subsystem employs a system transaction class which collects convenience routines and thereby maximizes code re-use. The system transaction class contains pointers to device transaction classes which correspond to each of the functional models in the simulation subsystem, but does not require instantiation of all of the device transaction classes and associated device objects. One or more configuration transaction classes derived from the system transaction class define transactions between selected ones of the functional models within the simulation subsystem. The configuration transaction classes inherit the convenience routines of the system transaction class, but cause instantiation of the respective functional models only when needed for a transaction.