This invention describes an improved high bandwidth chip-to-chip interface for memory devices, which is capable of operating at higher speeds, while maintaining error free data transmission, consuming lower power, and supporting more load. Accordingly, the invention provides a memory subsystem comprising at least two semiconductor devices; a main bus containing a plurality of bus lines for carrying substantially all data and command information needed by the devices, the semiconductor devices including at least one memory device connected in parallel to the bus; the bus lines including respective row command lines and column command lines; a clock generator for coupling to a clock line, the devices including clock inputs for coupling to the clock line; and the devices including programmable delay elements coupled to the clock inputs to delay the clock edges for setting an input data sampling time of the memory device.

High bandwidth memory interface

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

Systems, among other embodiments, include topologies (data and/or control/address information) between an integrated circuit buffer device (that may be coupled to a master, such as a memory controller) and a plurality of integrated circuit memory devices. For example, data may be provided between the plurality of integrated circuit memory devices and the integrated circuit buffer device using separate segmented (or point-to-point link) signal paths in response to control/address information provided from the integrated circuit buffer device to the plurality of integrated circuit buffer devices using a single fly-by (or bus) signal path. An integrated circuit buffer device enables configurable effective memory organization of the plurality of integrated circuit memory devices. The memory organization represented by the integrated circuit buffer device to a memory controller may be different than the actual memory organization behind or coupled to the integrated circuit buffer device. The buffer device segments and merges the data transferred between the memory controller that expects a particular memory organization and actual memory organization.

Memory system topologies including a buffer device and an integrated circuit memory device

An apparatus that reduces sampling errors for data communicated between devices uses phase information acquired from a timing reference signal such as a strobe signal to align a data-sampling signal for sampling a data signal that was sent along with the timing reference signal. The data-sampling signal may be provided by adjustably delaying a clock signal according to the phase information acquired from the strobe signal. The data-sampling signal may also have an improved waveform compared to the timing reference signal, including a fifty percent duty cycle and sharp transitions. The phase information acquired from the timing reference signal may also be used for other purposes, such as aligning received data with a local clock domain, or transmitting data so that it arrives at a remote device in synchronism with a reference clock signal at the remote device.

Apparatus for data recovery in a synchronous chip-to-chip system

A memory module includes a plurality of signal paths that provide data to a memory module connector interface from a plurality of respective integrated circuit buffer devices that access data from an associated plurality of integrated circuit memory devices. The memory module forms a plurality of “data slices” or a plurality of portions of the memory module data bus that is coupled to the respective integrated circuit buffer devices. Each integrated circuit buffer device is also coupled to a bus that provides control information that specifies an access to at least one integrated circuit memory devices. According to an embodiment, a SPD device stores information regarding configuration information of the memory module. In embodiments, at least one integrated circuit buffer devices access information stored in the SPD device. In a package embodiment, a package houses an integrated circuit buffer die and a plurality of integrated circuit memory dies.

Memory module including a plurality of integrated circuit memory devices and a plurality of buffer devices in a matrix topology

The primary objective of DRAM-dynamic random access memory-is to offer the largest memory capacity at the lowest possible cost. Designers achieve this by two means. First, they optimize the process and the design to minimize die area. Second, they ensure that the device serves high-volume markets and can be mass-produced to achieve the greatest economies of scale. SLDRAM-synchronous-link DRAM-is a new memory interface specification developed through the cooperative efforts of leading semiconductor memory manufacturers and high-end computer architects and system designers. SLDRAM meets the high data bandwidth requirements of emerging processor architectures and retains the low cost of earlier DRAM interface standards. These and other benefits suggest that SLDRAM will become the mainstream commodity memory of the early 21st century.

B. Vogley

Papers

SLDRAM: high-performance, open-standard memory