Design And Verification Of OSD Module In Video Display System

As the rapid development of science and technology today, a wide variety ofmodern electronic products are improving our life and work. In order to make theoperation more simple, more convenient and more intelligent, there is supposed to be arich graphic user interface(GUI), which display the function items, the system operationstatus, as well as a friendly message and so on, these functions is done by the OSD (OnScreen Display) in the system. OSD control system is very common in the electronicproducts, and is widely used. Therefore, the design of the circuit has higherrequirements: low cost, small size, low power consumption, powerful, and convenientto control, etc.To reach the above targets, this thesis proposed a new design architecture, whichcould improve the performance of OSD controller, and was convient to be applied in thehigh-quality electronic products. The thesis used the following technologies mainly:1. Co-operation between software and hardware. The software utilized theadvantages of convenient operation and modification and flexible configuration, while thehardware utilized the advantages of the high operation performance, etc. Theco-operation could enhance OSD controller work efficiency.2. The storage and access of OSD region with the link mode, it could dynamicallyallocate the storage space and arrange the link order. User could modify an OSD regionthough the software, it was easy to operate. It only needs to store valid data of eachregion, not the entire screen in memory, which greatly improved the system memoryspace utilization and reduced the bandwidth requirements.3. Taking the color indexing technology, OSD used the color index to look upLUT to generate the image data, under the premise of image quality, greatly reducing thesystem’s storage space and bandwidth. It was easy to adjust the image’s color, you onlyneed to change the color lookup table, not make changes to the data of OSD region, theoperation is convenient and simple.4. Clock gating was designed to reduce dynamic power consumption. It took thecombination of functional and non-functional enable, used a multi-level clock gateddesign, and took the measures of active and passive design, greatly reduce the powerdissipation of OSD controller. During the study of the design, the function of OSD is firstly divided into for thesoftware part and hardware part, and presented some features which the hardwareimplemented, developed the design architecture, and then modeled OSD function in thehigh-level language, finished feasibility assessment, and wrote RTL codes for hardwaredesign in Verilog HDL(Hardward Description Language). Finally the advancedverification methodology (OVM) was used to simulate the function, and the design wasintegrated into the system to be verified in the platform of FPGA. After testing andvalidation, confirmed the OSD controller achieve the desired goal.