Implementing enhanced wear leveling in 3D flash memories

摘要

A method, system and computer program product are provided for implementing enhanced wear leveling in a stack of flash memory chips. A flash memory includes plurality of flash memory chips including a number N data chips and one or more spare chips. To even wear among the plurality of flash memory chips, a memory controller for the flash memory periodically transfers data from a data chip to a current spare chip, the current spare chip becomes a data chip and the selected data chip becomes the current spare chip. Over time, each chip in the stack becomes the spare chip. If a chip becomes nonfunctional, whatever chip is currently the spare chip becomes a permanent data chip and no more rotating is done.

主权项

1. A method for implementing enhanced wear leveling in a stack of flash memory chips comprising:
providing the stack of the flash memory chips with a number N of active data chips and one or more spare chips; periodically transferring data from an active data chip to a current spare chip, the current spare chip becoming a data chip and the active data chip becoming the current spare chip; continuing the periodic data transfer from an active data chip to a current spare chip with each of the flash memory chips becoming the spare chip over a time interval to even wear among all the flash memory chips; and responsive to a chip failure, causing the current spare chip to become a permanent data chip ending the periodic data transfer.