Philips 2-chip solution
This set consists of two chips named by Philips as Hercules (e.g. TDA 120 X 1) and a Genesis Scalar (e.g. GM1501). The Hercules has its own embedded Flash memory for its start-up and processing routines. CVBS
from the tuner is directly fed into pin 24 and RGB output is obtained at pins 85–87 (Figure 16.16). Non-volatile RAM (NVRAM) stores customer settings such as brightness and colour as well as channel information. The Histogram carries out what is known as histogram equalisation of contrast, a process which spreads out the most-frequent intensity values across the picture. This allows areas of lower local contrast to gain a higher contrast without affecting the global contrast. It is most useful in images with back- grounds and foregrounds that are both bright or both dark. The scalar carries out all necessary functions to convert the incoming image format into the panel’s native format including interlace-to-progressive and scan con- version. The chip also incorporates an embedded LVDS transmitter/ encoder. Flash and NVRAM are external discrete chips. So SDRAM is used for field storage. The full set of functions is listed in Table 16.4.