Memory devices and methods adapted to process and generate analog data signals representative of data values of two or more bits of information facilitate increases in data transfer rates relative to devices processing and generating only binary data signals indicative of individual bits. Programming of such memory devices includes programming to a target threshold voltage range representative of the desired bit pattern. Reading such memory devices includes generating an analog data signal indicative of a threshold voltage of a target memory cell. Warning of cell deterioration can be performed using reference cells programmed in accordance with a known pattern such as to approximate deterioration of non-volatile memory cells of the device.