Rank determination algorithm by current comparing for rank modulation flash memories

Rank modulation is a new data representation method for flash memories that uses the relative orders of memory cell levels. With this innovative approach, flash memory reliability and storage capacity are improved at the same time. Previous rank modulation hardware used winner-take-all circuits for rank determination. In this paper a new rank determination strategy using current-mode comparison is proposed. Instead of a complex array of winner-take-all circuits, this scheme utilizes one row of current-mode comparators for the rank determination. The proposed flash memory circuits are less complicated, more area efficient, and require less power than the winner-take-all array approach.