 The display driver will typically accept commands and data using an industry-standard general-purpose serial or parallel interface, such as TTL, CMOS, RS232, SPI, I2C, etc.and generate signals with suitable voltage, current, timing and demultiplexing to make the display show the desired text or image.The display driver may itself be an application-specific microcontroller and may incorporate RAM, Flash memory, EEPROM and/or ROM.