A data processing system having high reliability and an operation method thereof are provided. The data processing system includes an arithmetic processing device including a nonvolatile memory and/or a nonvolatile register, and a monitoring system for monitoring an operation state of the arithmetic processing device. The monitoring system is a system utilizing artificial intelligence, and has a function of estimating from a program operating on the arithmetic processing device how much and which location of the arithmetic processing device will increase in temperature when the program operates. When the monitoring system estimates that the temperature of part of the arithmetic processing device will exceed a threshold value when the program operates, the monitoring system transmits an instruction to lower a clock frequency of the part of the arithmetic processing device, reduce a power supply potential of the part, or interrupt power supply to the part.