Apple Inc.

Advanced Memory International, Inc.

Donald N North

David V James

Glen D Stone

Brent Keeth

Troy A Manning

Peter B Gillingham

Terry R Lee

Kevin J Ryan

Cormac Michael O'Connell

Bruce Millar

Yoshikazu Morooka

Henry Stracovsky

Desi Rhoden

Hans A Wiggers

David B Gustavson

Jean Crepeau

A method and system for purging translation lookaside buffers (TLB) of a computer system are described. Directed write transactions can be used to avoid deadlock and avoid the need for additional bridge buffers. Broadcast emulation can be achieved by linking the nodes in a doubly-linked list and having neighboring nodes notify each other of changes in TLB entries.

Method and system for supporting multiprocessor TLB-purge instructions using directed write transactions

A SLDRAM System is provided with a plurality of in-circuit, calibratable memory modules and a memory controller for issuing unicast and multicast command packets to the memory modules. Command packets are transmitted over a unidirectional command link that includes a complementary pair of command clock lines, a command FLAG line and a plurality of noncomplemented command bit lines. Each of the command clock lines, command bit lines and the FLAG line is a SLIO transmission line. Data transfer operations are carried out in response to the command packets over one or more bidirectional data links that each includes two complementary pairs of data clock lines, and a plurality of noncomplemented data bit lines. Each of the data clock lines and the data bit lines is a SLIO transmission line. Each SLIO transmission line is single-end terminated and preferably tapped into by way of stub resistors.

Memory system having synchronous-link DRAM (SLDRAM) devices and controller

A system and method for avoiding starvation and deadlocks in a split-response-bus multiprocessor computer system. The multiprocessor computer system includes a first node and a second node coupled to the a split-response bus, wherein the first and second nodes communicate by passing request packets over the split-response bus. The method and system includes providing precedence information in the request packets, and then using the precedence information when receiving the request packets to determine which request packets to process and which request packets to reject when a conflict occurs.

Method and system for avoiding starvation and deadlocks in a

A system for efficiently supporting critical-word-first data transfers comprises a data storage device, a controller, a data selector, and a multiplexer. The data storage device is preferably capable of outputting data in one or more word orderings. The controller is preferably a state machine that processes data transfer requests by determining the orderings of data that the associated data storage device, data selector and multiplexer can provide, determining the ordering for the data requested and creating a response packet with the data ordered in critical-word-aligned order beginning with the word containing the requested address. The present invention also includes a method for efficiently supporting critical-word-first data transfers. The method includes the steps of: monitoring the bus for a data request packet; determining the desired order for the requested data; determining the transmission orders in which the data storage device can provide the data; determining the transmission order best matching the requested order and creating a response packet with the data ordered in the order best matching the desired requested order; adding response format information to the header of the response packet and transmitting the response packet on the bus.

System for generating and sending a critical-world-first data response

An apparatus for performing indivisible memory operations on memory locations in remote memory means in multiple bus, multiple processor computer systems comprises a logic supervisor coupled to a bus bridge. The logic supervisor comprises a lock address register, a buffer address register, a command register, a first parameter register, a second parameter register, a first latch, a second latch, a comparator, and a controller. The controller is a state machine that observes instruction sequences intended to create an indivisible memory operation on a remote bus. When the logic supervisor detects an indivisible memory operation instruction sequence with a remote address, it gathers the data for the indivisible memory operation, inhibits the processor, and hands the data off to the bus bridge. When the logic supervisor receives a completion status from the bus bridge it places the returned value in memory and releases the processor. Should the logic supervisor detect an indivisible memory operation instruction sequence, but not a remote address, the logic supervisor does not participate in the indivisible memory operation.

System and method for executing indivisible memory operations in

A multi-processor computer system comprising a data storage device, a memory controller, and a plurality of processors. The data storage device has a plurality of memory lines, each memory line having a portion for alternatively storing data or, a set of GONE codes, a count value, and a processor identification code value. A memory controller coupled to the data storage alternatively stores and retrieves data or the GONE code, the count field value and the processor identification code value. At least one of the processors includes a cache memory and a cache memory controller. The cache memory controller compares a GONE code associated with the requested memory line with the contents of the requested memory line, and requests the contents of the requested memory line from a second of the processors in response to the comparison.

System and method for preventing stale data in multiple processor

An elasticity buffer for use in a data transmission system having a transmitter and a receiver and utilizing a data transfer protocol that periodically supplies an elasticity element that can be deleted or replicated by the elasticity buffer to maintain the synchronous transfer of data elements. The elasticity buffer includes: a memory array and at least one flag per memory location operative to be set to a first or second state; a write controller operating at the transmitter clock for writing the data elements into the memory locations in a sequential order and setting the corresponding flags; a read controller operating at the receiver clock for reading the data elements from the memory locations in the sequential order; and a flag controller for reading the flags, determining if the transmitter clock is faster or slower than the receiver clock from the pattern of flags read from memory, communicating a delete signal to the read controller to delete an elastic symbol if the transmitter clock leads the receiver clock, and communicating a replicate signal to the read controller if the transmitter clock lags the receiver.

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Saratoga, CA, United States of America

Donald N North