In semiconductor devices with nonvolatile memory modules embedded therein, a technology is provided which facilitates evaluation of the nonvolatile memory characteristics. An MCU includes a CPU, a flash memory, and an FPCC that controls write or erase operations to the flash memory. The FPCC executes a program used to perform write or other operations to the flash memory, thereby performing write or other operations to the flash memory in accordance with a command issued by the CPU. In the MCU, the FCU is configured to execute test firmware to evaluate the flash memory. In addition, a RAM can be used by both the CPU and FCU.