Driver unit for driving an active matrix LCD device in a dot reversible driving scheme

An LCD driver in a drive unit for driving a plurality of data lines of an LCD panel, said LCD driver comprising:

• a plurality of circuit blocks arranged in an internal circuit of a semiconductor chip, each of said circuit blocks having a data register block including a plurality of data registers each for receiving a display data for one of the data lines, a D/A converter block including a plurality of P-ROM decoders and a plurality of N-ROM decoders each disposed for a corresponding one of said data registers to output an analog gray-scale signal, and an output stage block each disposed for a corresponding one of said P-ROM decoders and said N-ROM decoders, said output stage block driving a corresponding one of the data lines based on an output from a corresponding one of said P-ROM decoders and said N-ROM decoders, and a switching system for switching the display data and the analog gray-scale signal so that adjacent two data lines receive the analog gray-scale signals having opposite polarities and also receive alternately the analog gray-scale signal having a positive polarity and the analog gray-scale signal having a negative polarity,
• said plurality of P-ROM decoders and said plurality of N-ROM decoders forming a N-ROM decoder block and a P-ROM decoder block, respectively, which are arranged consecutively along a side of the semiconductor chip.