Design and Implementation of OSD in Digital Video Processing ASIC
Yang Ming-wu · Video Engineering · 2011
A new OSD system is designed in a digital video processing ASIC which can be applied in modern TV sets and monitors.It reads fonts and attributes contents from build-in SRAM,then represents OSD information by RGB datas according to its attributes,a alpha blending engine will overlay OSD information onto video according to programmable alpha value at last.Many functions of this OSD engine are user-defined,it adopts the proposed storage structure of 1/2/4 bpp fonts and characters in build-in SRAM to support more number of fonts or characters.It can execute non-linear scale up display,as well as vast specific functions such as flashing,shadowing,transparency,fonts or characters double height or width,programmable columns and rows and so on.The chip is designed and fabricated by UMC 0.18 μm CMOS process,and the OSD engine can work well at frequency reach up to 170 MHz.