Abstract: A self-raster circuit of a monitor capable of providing color rasters to a cathode ray tube of the monitor if no video signal is inputted to the monitor from a computer. The self-raster circuit includes a detecting section for detecting whether or not a video signal is inputted to the monitor from the computer, and a control section for outputting a variety of pulse-width-modulated signals corresponding to predetermined colors to a video amplifying section of the monitor if it is detected by the detecting section that no video signal is inputted from the computer.

Abstract: An apparatus for controlling the operation of a display data channel part of a monitor so that a personal computer (PC) with DDC function is compatible with a personal computer without DDC function and a method thereof.

Abstract: An apparatus and method for serial data communication capable of performing an inter integrated circuit (I.sup.2 C) serial data communication utilizing a general microcomputer having no built-in hardware for the I.sup.2 C serial communication. In the apparatus, a start condition for a start of serial data transmission or reception is detected by a start condition detecting section utilizing an input serial clock signal and serial data of an I.sup.2 C communication type, and a stop condition for a stop of the serial data transmission or reception is detected by a stop condition detecting section utilizing the serial clock and serial data. A microcomputer generates and releases an interrupt for the serial data transmission or reception in accordance with start and stop signals provided from the start and stop condition detecting sections, respectively, and then performs transmission or reception of the serial clock signal and serial data when the interrupt is generated.