A power up detection method for a memory device and a memory device are disclosed. In a first phase, a test word is read from a read-only memory (ROM) row of a memory array of the memory device, and the test word is compared to predetermined ROM row data. If the test word matches the predetermined ROM row data, a second phase may be performed. In the second phase, first user data is read from a user-programmed row of the memory array at a first time. Second user data is read from the user-programmed row of the memory array at a second time different from the first time. The first user data is compared to the second user data. Successful power up of the memory device is determined when the first user data matches the second user data.
