Patent ID: 6285607
Filing Date: 2001-09-04
Classification: G11C

Abstract:
A memory system (10) comprising:a plurality of memory devices (42), where at least one of the memory devices has a defective memory location;defect mapping means (46) associated with each memory device having a defective location, for recording a representation of the location of the or each defective memory location;a controller (17) for accessing the defect mapping means and for writing data structures to and reading data structures from the memory devices; andhost interface means (16) for conveying a host address and associated data structures between a host (12) and the controller;the system being arranged and configured so that data structures are divided into portions which are respectively stored in different memory devices, and, in use, the controller (17) converts the host address to an intermediate address for use in accessing a memory location in each of a plurality of said devices, accesses the defect mapping means using said intermediate address and thereby generates on a per device basis, for each device of said plurality of devices, a physical address corresponding to a non-defective location within that device by incrementing a first physical address in the physical address space of that device, which first address is determined from said intermediate address, by a number of addresses ordered sequentially after said first address according to a predetermined order of physical addresses in the physical address space of that device, so as to obtain a final physical address corresponding to a non-defective location in that device, the number of addresses by which said first address is incremented being related to the number of defective memory locations prior to said first address, and any defective locations between said first and final physical addresses, according to said predetermined order, whereby different physical addresses may be applied to different devices when a data structure is written to or read from the different devices.