LCD Signals and Timing

LCDs require the following basic timing signals:

  • VSYNC (Vertical Sync for TFT) or FP (Fr ame Pulse for STN)
    • Used to reset the LCD row pointer to top of the display
  • HSYNC (Horizontal sync for TFT) or LP (Line Pulse for STN)
    • Used to reset the LCD column pointer to the edge of the display
  • D0..dXX (1 or more data lines)
    • Data line function varies in STN and TFT modes and panel type
  • LCDCLK (LCD clock)
    • Used to panel control refresh rate

Some panels may require additional timing signals:

  • STN panels usually require MDISP (AC bias)
    • Used for AC bias (to prevent panel damage)
    • Used to indicate valid data on the LCD data bus
  • Other signals some optional
    • LCD power, backlight power, touchscreen