Nonvolatile semiconductor memory device and signal processing system

The nonvolatile semiconductor memory device includes: a first memory block having a first program level and a first read circuit; a second memory block having a second program level different from the first program level and a second read circuit of a scheme different from the first read circuit, the second memory block being formed on the same substrate as the first memory block; and a data output circuit for selecting either the first read circuit or the second read circuit and outputting data read via the selected read circuit externally.