[Country EMBED strategy] [060] [LCD working principle analysis]

LCD hardware System

1.LCD LCD Screen

Liquid crystals belong to an organic compound, the molecular shape of a long rod, under the action of different currents, the molecules will have a regular rotation, so that the light produced a certain control to form a pixel, and many pixels right can form a complete image.

The LCD is the abbreviation for liquid Crystal display. The liquid crystal display can be divided into TFT, GF, STN and so on, wherein TFT screen is used frequently in embedded system.

2.LCD driver ICS

The LCD driver chip is a module that controls the change of the liquid crystal molecule, which provides the voltage for the deflection of the liquid crystal molecule. Usually, the LCD driver chip and LCD panel to do a piece of the circuit board.

3.LCD Controller

1. The liquid crystal should be able to display the image normally, in addition to the LCD driver chip, but also have LCD controller to provide the necessary data and control signal to the LCD driver chip. Most ARM processors are internally integrated with LCD controllers.

2.REGBANK Register Group, 17 registers.

3.LCDCDMA the picture to display, placed in the memory frame cache (fixed position in memory), LCDCDMA is similar to the DMA automatically reads the picture to display in memory, does not require processor intervention.

4.VIDRPCS reads the data and registers the control information composing data sends to the LCD driver chip.

5.TIMEGEN produces the displayed timing control signal.

LCD display and Signal

VCLK pixel clock signal, showing the time interval between two points

HSYNC Horizontal sync signal, display a line of time

VSYNC Vertical sync signal that shows the time of a frame, that is, the time of all rows

VD[23:0] LCD pixel data output port

Vden Data Enable signal

LEND Line End Signal

[Country EMBED strategy] [060] [LCD working principle analysis]