1. A method comprising: in a data storage device including a memory and an error correction coding (ECC) engine, performing: storing a first ECC page including a data block and first main ECC data to the memory, the first main ECC data enabling the ECC engine to correct errors in the first ECC page; and storing a second ECC page including first additional ECC data to the memory, the first additional ECC data enabling the ECC engine to correct errors in a single sub-block of multiple sub-blocks within the data block, wherein the memory is a three-dimensional (3D) memory including one or more memory cells, and wherein the data storage device includes circuitry associated with operation of the one or more memory cells.