Patent ID: 8458566
Filing Date: 2013-06-04
Classification: G06F,G11C

Abstract:
1. A method for performing copy back operations, comprising: sending a copy back command to a flash memory for reading a first error correction code (ECC) data from a first address; receiving the first error correction code from the flash memory; decoding the first ECC data without performing error correction to calculate a fail count of the first ECC data; comparing the fail count with a first threshold value, wherein when the fail count is less than the first threshold value, a first program command is sent to the flash memory for storing the first ECC data to a second address of the flash memory; comparing the fail count with a second threshold value; performing partial error correction when the fail count is greater than the first threshold value and less than the second threshold value, correcting at least one error segment of the first ECC data to obtain at least one corrected data segment; encoding a partial parity according to the corrected data segment; sending the corrected data segment and the partial parity to the flash memory; and after the flash memory amends the first ECC data according to the corrected data segment and the partial parity to obtain a second ECC data, sending a second program command to the flash memory for storing the second ECC data to the second address of the flash memory.