DYNAMIC MANAGEMENT OF PROGRAMMING STATES TO IMPROVE ENDURANCE

摘要

A storage device with a memory may include improved endurance and programming speed by modifying the programming states of the memory blocks. For example, the blocks may be three bit memory blocks, but a dynamic reassignment of verify levels and read margins can result in the block acting like a two bit memory block. Memory blocks may be designed for a certain number of bits per cell (i.e. number of states) and the programming is based on that number. However, single level cell (SLC) programming is still possible in addition to programming according to the number of bits per cell that the memory is designed for. Multiple SLC programming steps can be used to modify the number of states for certain memory cells by the memory controller.

主权项

1. A method for reassigning programmed states in a multi-level cell (MLC) memory block of at least three bits per cell, the method comprising:
performing a first programming of original data to the MLC memory block using a program verify for single level cell (SLC) programming; adjusting a read verify for a second programming wherein the adjusted read verify establish a number of states that correspond with a lower number of bits per cell than the at least three bits per cell; and second programming new data using the adjusted read verify.