Memory controller with flexible data alignment to clock

摘要

A system includes a memory controller and a plurality of memory devices that are connected in-series to the memory controller. The system operation is synchronous with clock that is provided in a fashion of source synchronous clock structure. The source synchronous clock structure includes a PLL (Phase-Locked Loop) that reshapes an incoming clock and a reshaped clock is provided. The PLL provides a shifted clock in phase of 90°. The phase-shifted clock and data are transmitted from the first device to the second device. Clock phase shift provides a center-edge clock with data to be transmitted. The devices are assigned with unique IDs. The least significant bit of the ID number of the last device is used for determination of clock alignment: edge- or center-aligned clock with data produced by the memory controller.

主权项

1. An apparatus for communicating with a plurality of devices connected in-series that employs source synchronous clocking, the apparatus comprising:
an information detector for detecting number information relating to the number of devices connected in-series; and a clock producer for producing a clock signal in response to the detected number information, the produced clock signal being used for synchronizing communication between the apparatus and the devices.