ML610Q174 User’s ManualChapter 25 LCD DriversFEUL610Q174-01 25-1925.3 Description of Operation25.3.1 Operation of LCD Drivers and Bias Generation CircuitFigure 25-4 shows the operation of the LCD drivers and the bias generation circuit.Figure 25-4 Operation of LCD Drivers and Bias Generation Circuit1 System reset causes the LCD drivers to stop operation and the segment port which is the combination with ageneral-purpose port will function as a general-purpose port, and will be in a HiZ output state.2 External division resistance and built-in division resistance are chosen with a bias mode register (BIASMOD).3 Segment port output is selected by the LCD port segment register (LSELS1,2,4). VSS level is outputted to eachsegment port.4 1/2 bias or 1/3 bias is selected by the bias circuit control register (BIASCON).5 Frame frequency and duty are set up with a display mode register(DSPMOD).6 Display data (DSPR00 to DSPR17, DSPR20 to DSPR27) is set as an display register..7 LCD is set as display mode by LMD1, LMD0 bit of a display control register (DSPCON).( A display waveform isoutputted to each segment port.)ResetRESET_NLMD1, LMD0Common outputCOM0 to COM3Segment outputSEG8 to SEG23SEG32 to SEG39V SSVSSCommon output waveformSegment output waveform① ⑦④⑤⑥HiZ output③Segment outputSEG0 to SEG7 VSS Segment output waveform②HiZ output
