Rambus Inc.
COORDINATING MEMORY OPERATIONS USING MEMORY-DEVICE-GENERATED REFERENCE SIGNALS

Abstract:

A memory system includes a memory controller coupled to multiple memory devices. Each memory device includes an oscillator that generates an internal reference signal that oscillates at a frequency that is a function of physical device structures within the memory device. The frequencies of the internal reference signals are thus device specific. Each memory device develops a shared reference signal from its internal reference signal and communicates the shared reference signal to the common memory controller. The memory controller uses the shared reference signals to recover device-specific frequency information from each memory device, and then communicates with each memory device at a frequency compatible with the corresponding internal reference signal.