Acer X203H Acer X203H Service Guide - Page 58

III. Circuit Implementations: A.) THE MAIN BODY: A-1.) Interface board block diagram : INT E RFA CE B O A R D 1600x900 LCM M CU RTD 2120L EEPROM ATM EL 24C 16 S ca la r RTD 2545LH (Support HDCP) D C +3.3V D C +1.8V CTRL BD DVI VGA (a) Circuit operations: A basic operation theory for this interface board is to convert analog signals of Red, Green and Blue to digital signals of Red, Green and Blue. The scaling IC has internal A/D converter, internal OSD, built in LVDS transmitter and auto-detect input timing functions. A/D converter is convert analog signal to digital data. OSD is offering adjustable functions to end-user. Detect timing is for detect change mode. LVDS transmitter is used to compress the digital RGB data, the Hsync, Vsync and pixel clock generated by Scaling then output to LCD module. MCU stores source code and offers H/W DDC2Bi function & controls system processing. EEPROM is stored DDC and HDCP data, OSD common data and user mode data. (b) IC introduction: 1.) DDC (Display Data Channel) function: We use DDC IC to support DDC2Bi function. DDC data is store in 24C02 (EEPROM). Those data related to LCD monitor specification. PC can read them by "SDA" and "SCL" serial communication for I²C communication for DDC2Bi. 2.) Scalar IC: There are A/D, TMDS receiver, HDCP, Scaling, OSD and LVDS transmitter functions built-in the RTD2545LH IC. Scaling IC is revolutionary scaling and color engine, - 58 -