Short q-ary WOM codes with hot/cold write differentiation

We construct new WOM codes with practical design considerations. First the problem of 2 cell q-ary WOM codes is addressed with a construction that uses lattice tilings. The resulting codes for arbitrary numbers of input bits are shown to be within a small additive constant from the capacity. Then we introduce a new model of WOM codes that support data bits with different update requirements. Differentiation between frequently written (hot) bits and rarely written (cold) ones allows a large number of re-writes while leveling the wear between the hot and cold input bits.