Patent ID: 7636867
Filing Date: 2009-12-22
Classification: G06F,G11C

Abstract:
1. A memory system with a hot swapping function being a serial-transmission type memory system comprising a row of a plurality of memory modules sequentially connected to one another in series and a memory controller provided with a first input-output section and a second input-output section, wherein said memory controller, to said first input-output section of which one end of the row of the plurality of memory modules is connected, ordinarily performs operations of reading and writing data by accessing each of the memory modules through a first read signal line and a first write signal line and exerts control so that, when a failure occurs in any of the memory modules, by disconnecting a defective memory module from the memory module in its preceding stage and by sequentially connecting the memory modules contained in the row of the memory modules in next and onward stages subsequent to the defective memory module and a spare memory module connected to another end of the row of the memory modules to said second input-output section of said memory controller in series through a second read signal line and a second write signal line to gain access to each of the memory modules, said memory controller is able to withdraw said defective memory module and to insert a memory module for replacement, wherein said memory system is constructed so that said memory controller, when a failure occurs in any one of the memory modules contained in the row of the memory modules, disconnects the defective memory module from the memory modules in succeeding stages and connects the memory modules in the succeeding stages to said second input-output section through the spare memory module and, with the defective memory module disconnected from the memory module in the preceding stage, copies data stored in the defective memory module into the spare memory module and, after completion of the copying, replaces the defective memory module with the spare memory module to gain access to each of the memory modules from said second input-output section and, after the replacement of the defective memory module, copies data stored in the spare memory module into the memory module used to replace the defective memory module and, after completion of the copying, with the memory module used to replace the defective memory module connected to the memory modules in preceding and succeeding stages, gains access to each of said memory modules from said first input-output section thereafter.