A display driver includes a control register; a memory control circuit which controls EEPROM access; and a register write circuit which writes a display characteristic control parameter that has been read from EEPROM to the control register at power-on, at a system reset, or at refresh timing (during a non-display period), to perform initialization processing or refresh processing for the control register. The register write circuit writes refresh period information or manufacture information that has been read from the EEPROM to the control register. MPU access is inhibited during the writing of the display characteristic control parameter to the control register.