Rapid RAM Initialization Using ECC Dirty Flags
AssigneeSilicon Laboratories Inc.
InventorThomas David
Life of this patent
Estimating the term…
Abstract
A system and method for rapid initialization of an ECC protected memory is disclosed. Rather than rewriting the entire memory after each power up or return from a low power mode, the present system adds an additional ECC Dirty flag to each data word in the ECC protected memory. This ECC Dirty flag is used to signify whether the data word and its associated ECC symbol have been written since the last power up. If the data word has not been written, then the generation of an ECC error is disabled. The ECC Dirty flags are written after power up with a first value to indicate that the data word and its associated ECC symbol have not been written. When writes are performed to the data word, the ECC Dirty flag is written with a second value. This second value enables the generation of ECC errors.
Claims20
A device allowing rapid initialization of an Error Correction Code (ECC) protected memory, comprising:
- a processing unit;
- a data memory device, organized as:
- a plurality of data words;
- an ECC symbol associated with each of the plurality of data words;
- and
- an ECC Dirty Flag associated with each of the plurality of data words;
- and
- an ECC circuit, where the ECC circuit does not indicate an ECC error for a data word if the ECC Dirty Flag associated with that data word is set to a first value, indicating that the data word and associated ECC symbol have not been written since a last power up or return from a low power mode.
A method for quickly initializing and operating an Error Correction Code (ECC) protected memory, comprising:
- associating an ECC Dirty Flag with each data word in the ECC protected memory;
- writing the ECC Dirty Flag to a first value that indicates that the data word and associated ECC symbol have not been written since a last power up or return from a low power mode;
- and
- writing the ECC Dirty Flag to a second value when the data word and associated ECC symbol are written;
- wherein an ECC error cannot be indicated for the data word if the associated ECC Dirty Flag is set to the first value.
A device allowing rapid initialization of an Error Correction Code (ECC) protected memory, comprising:
- a processing unit;
- a data memory device, organized as one or more banks, wherein each bank comprises:
- a plurality of data words;
- and
- an ECC symbol associated with each of the plurality of data words;
- one or more ECC Dirty Flag memories, each associated with one of the one or more banks, wherein one bit in the ECC Dirty Flag memory is associated with each data word in the data memory device;
- and
- an ECC circuit, where the ECC circuit uses the data word to generate the ECC symbol on a write operation and uses the data word, the ECC symbol and the bit in the ECC Dirty Flag memory associated with the data word to generate an ECC error to the processing unit on a read operation.
Dependencies are inferred from the claim text.