A peripheral circuit with a host load adjusting function which is capable of readily carrying out control so that the amounts of data processed by the peripheral circuit and a host CPU are balanced by limiting interrupts made by the peripheral circuit, usage of a memory bus bandwidth, and a processing throughput of data. A typical embodiment of the present invention has an adjustment limitation setting unit setting a minimum value of an interval of interrupt requests generated by the peripheral circuit with the host load adjusting function, and a cycle counter counting generation timing of the interrupt requests, and compares a value of the cycle counter with the interval set in the adjustment limitation setting unit, thereby suppressing the interrupt requests generated at an interval shorter than the set interval.