Multicasting system for selecting a group of memory devices for operation

Abstract

A system and method for multicasting control signals to selectively operate one memory device or groups of memory devices comprises a memory controller coupled to a plurality of memory devices by a command bus and a data bus. Each of the plurality of memory devices has a unique identification number. The system provides an addressing scheme in which an individual memory device or groups of memory device can be selected for operation by addressing the devices with a command packet. The memory controller broadcasts a command packet over the command bus to the plurality of memory devices. The packet includes an identification number. At each of the memory devices, selection logic is included to make the memory device operational if the identification number in the packet matches the identification number assigned to the memory device. The address in the packet is preferably encoded such that identification number has the same size regardless of whether a single memory device is being selected for operation or a group of memory devices are being selected for operation. The present invention also includes a method for selecting groups of memory devices for operation by multicasting a select address comprising the steps of: providing an memory identification number to each memory device, transmitting an memory device selection address, comparing the memory device selection address to the memory identification number, and asserting a signal to make the memory device operational if the memory device selection address and the memory identification number match.