Abstract: A circuit arrangement and method are used in connection with a data latch that is coupled to a data source over a source synchronous communications interface to disable the data latch from latching data whenever the data source is not driving the source synchronous data strobe signal. As such, when the data source is not driving the source synchronous data strobe signal, undesired and/or inadvertent latching by the data latch can be avoided. Moreover, in implementations where a data strobe signal line is bidirectional, and capable of being driven either by the data source or by another circuit used to access the data source (e.g., a memory controller), disabling data latching as described herein can minimize the risk of driver damage resulting from conflicting attempts to drive the data strobe signal line at both ends.

Abstract: A method and system for transmitting address commands in a multiprocessor system comprising multiple nodes interconnected by an address bus. A request for arbitration of an address bus is transmitted from a controller within a node of multiple nodes to an arbitration switch, which controls transmission across the address bus. The address command is transmitted from the controller to the arbitration switch, in response to receiving a grant of arbitration of the address bus. The address command is then broadcast from the arbitration switch to a controller within each node of multiple nodes, in response to receiving the address command at the arbitration switch. The address command is broadcast from the controller within each node, in response to receiving the broadcast address command at the controller within each node, such that all address command transmissions on the address bus are transmitted to each processor within a multiprocessor system.

Abstract: A method and system for improving DRAM performance using burst refresh control reduces the overhead associated with refreshing DRAM in a computer system, making the memory more available to the devices that access it. Limiting the burst cycle to less than the entire DRAM array provides a lower latency than existing full DRAM burst techniques.

Abstract: A data transfer method and apparatus are provided for transferring data in a computer system on a high-speed synchronous multi-drop bus. Multiple devices including at least a first group of a plurality of devices and a second group of at least one device are connected to the high-speed synchronous multi-drop bus. To transfer data between devices in the first group, a first unidirectional data valid signal is applied to each device in the second group. The data from a sending device in the first group is transferred to a designated device in the second group. A second unidirectional data valid signal is applied to each device in the first group. The data is transferred from the designated device in the second group to a selected device in the first group.

Abstract: A shared bus non-sequential data ordering method and apparatus are provided. A maximum bus width value and a minimum transfer value are identified. A minimum number of sub-transfers is identified responsive to the identified maximum bus width value and the minimum transfer value. A bus unit having a maximum number of chips to receive and/or send data receives data in a predefined order during multiple sub-transfers. During each data sub-transfer, a corresponding predefined word is transferred to each chip of the bus unit.