Memory device and method for testing reliability of memory device

A method for testing reliability of a memory device,

• the memory device including memory array circuitry that stores content data, random number generator circuitry that generates a true random number, and memory controller circuitry that connects to the memory array circuitry, the method comprising:
• performing, by the memory controller circuitry, a reliability test only on the memory array circuitry out of the memory array circuitry and the random number generator circuitry on receipt of a first test command from an external device;
• and
• performing, by the memory controller circuitry, a reliability test only on the random number generator circuitry out of the memory array circuitry and the random number generator circuitry on receipt of a second test command from the external device, wherein
• the memory controller circuitry includes a self-test circuit that performs the reliability test of the random number generator circuitry, and
• the self-test circuit (i) starts checking irreproducibility of random number values, which are generated by the random number generator circuitry, on receipt of input of count information for specifying a number of counts to cause the random number generator circuitry to generate the random number values, and (ii) sends a check result to the external device on completion of checking.