Storage of data in data stores having some faulty storage locations

A method of storing data in data storage bits within a data store in a data processing apparatus, said data store storing blocks of data, said method comprising the steps of:

• determining which data storage bits within said data store are faulty data storage bits;
• grouping together groups of at least two blocks within said data store, such that for each group at least one of said data blocks has a non-faulty data storage bit for each of said plurality of data storage bit locations in said data blocks and storing information about said groupings in a group store;
• storing indicators for each group of data blocks within a selector store, said indicators indicating which data storage bits within said grouped data blocks are said faulty data storage bits;
• storing data in said blocks in said data store, such that if data is to be stored in a block present in one of said groups of blocks, said data is stored in each of said blocks within said group;
• and
• in response to an instruction to access said data store, determining from said group store if said data to be accessed is in a block that has been grouped with at least one further block and, if the block has not been grouped with at least one further block, then access said block, and if the block has been grouped with at least one further block, then access each bit of said data from a particular one of said data blocks within said group in dependence upon said stored indicators for said group such that no faulty data storage bits are read.

Data storage control circuitry for controlling storage and retrieval of data from a data store, said data store including data blocks, each of said data blocks comprising a plurality of data storage bits, said data store comprising at least one faulty data storage bit within at least some of said data blocks, said data storage control circuitry comprising:

• a group store associated with said data store for storing information grouping together an odd number of at least three data blocks each of said at least three data blocks having at least one faulty data storage bit, said data blocks grouped such that a majority of said data blocks within a group do not have a faulty data storage bit in a same location;
• data storage logic, responsive to an instruction to store data in a data block that is present in one of said groups of data blocks, for storing said data in all of said data blocks within said group;
• and
• data access logic for controlling retrieval of data from said data store, said data access logic responsive to an instruction to read data from a data block appearing in one of said groups of data blocks, to compare each bit of data from said data blocks within said group and for each bit of data to output a value stored for said bit of data by a majority of said data blocks.

A method of storing data within a data store in a data processing apparatus, said data store storing blocks of data in a plurality of data storage bits, said method comprising the steps of:

• determining which data storage bits within said data store are faulty data storage bits;
• grouping together an odd number of at least three data blocks each having at least one faulty data storage bit, said data blocks being grouped such that a majority of said data blocks within a group do not have a faulty data storage bit in a same location;
• storing data in said blocks in said data store, such that if data is to be stored in a block present in one of said groups of blocks, said data is stored in each of said blocks within said group and storing information about said groupings in a group store;
• and
• in response to an instruction to access said data store, determining from said group store if said data to be accessed is in a block that has been grouped with at least two further blocks;
• if said data to be accessed has not been grouped, then access said block;
• and
• if said data to be accessed has been grouped, then compare each bit of data from said data blocks within said group and, for each bit of data, output a value stored for said bit of data by a majority of said data blocks.