Memory module with timing-controlled data paths in distributed data buffers

What is this patent about?

’035 is related to the field of high-density memory modules, specifically those utilizing a distributed architecture to manage signal integrity and timing across multiple ranks of memory devices. It addresses the challenges of maintaining synchronized communication between a memory controller and numerous memory chips as operating speeds increase and signal propagation delays become significant relative to clock cycles.

The underlying idea behind ’035 is the delegation of timing autonomy to localized buffer circuits distributed across the module board. Rather than relying on the central memory controller to manage the minute skew and latency variations for every chip, each buffer independently learns the necessary timing offsets by observing signal relationships during an initial memory operation. This allows the module to dynamically compensate for physical trace lengths and electrical loading without requiring complex, hard-wired leveling from the controller.

The claims of ’035 focus on a memory module architecture where a central control device manages command signals while a plurality of distributed buffer circuits handle the data and strobe paths. These buffers are positioned specifically to correspond with distinct sets of memory devices and contain internal logic that captures timing information from a prior memory transaction to calibrate the data and strobe signal alignment for subsequent operations.

In practice, the system functions by having the buffers monitor the interval between receiving a module-level control signal and the arrival of data from the controller during a write sequence. This captured phase relationship is then used to precisely time the launch of read data back to the controller. By localizing this intelligence, the module ensures that data from different parts of the board arrives at the controller interface simultaneously, effectively masking the physical layout complexities of the module.

This approach differs from prior solutions that relied on rigid 'fly-by' topologies or global leveling performed by the memory controller, which often struggle with metastability and phase drift at high frequencies. By utilizing distributed buffers that act as local timing masters, the invention allows for higher memory densities and faster clock rates while presenting a simplified, uniform electrical load to the host system.