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LCD display timing

# What is Active area?

Ans: Active area is the visible resolution.

 

# What is blanking area?

Ans: Blanking area is the period between each line (horizontal blanking) and each frame (vertical blanking). This was originally to give CRT monitors time to move the electron guns. LCD monitors don’t need as much time, so the blanking area can be reduced.

Blanking area= front porch + sync width + back porch

 

# What is horizontal front porch (HFP)?

Ans: Numbers of pixel clock pulses between the last valid pixel data in the line and the next H-Sync pulse. It is also known as sync offset, is basically the number of pixel clock before the sync pulse

 

# What is horizontal back porch (HBP)?

Ans: Numbers of pixel clock pulses between H-Sync signal and the first valid pixel data in the line. It is also known the number of pixel clock after the sync pulse, before the start of the active pixels

 

# What is H-sync pulse width?

Ans: Number of pixel clk pulses when a H-SYNC signal is active. It is the duration of the horizontal sync pulse. The sync pulse marks the start of the next line (horizontal sync).

 

# What is H-sync polarity?

Ans: Value of H-SYNC to indicate the start of a new line (active LOW or HIGH).

 

# What is Vertical Front Porch(VFP)?

Ans: Number of lines (HSYNC pulses) between the last valid line of the frame and the next VSYNC pulse. It is also known as sync offset, is basically the number of lines before the V sync pulse.

 

# What is Vertical back porch(VBP)?

Ans: Number of lines (HSYNC pulses) from a VSYNC signal to the first valid line.

It is also known the number of lines after the sync pulse, before the start of the active lines.

 

# What is V-SYNC pulse width?

Ans: Number of H-SYNC pulses when a VSYNC signal is active. It is the duration of the vertical sync pulse. The sync pulse marks the start of the next frame (vertical sync).

 

# What is V-SYNC polarity?

Ans: Value of V-SYNC to indicate the start of a new frame (active LOW or HIGH)

 

# What is Active frame width?

Ans: Horizontal resolution

 

# What is Active frame height?

Ans: Vertical resolution

 

# What is Screen width?

Ans: Number of pixel clk between the last HSYNC and the new HSYNC. Screen width = Active frame width + HBP + HFP.

 

# What is Screen height?

Ans: Number of lines between VSYNC pulses. Screen Height = Active frame height + VBP + VFP.

 

# What is Refresh rate (Vertical frame rate)?

Ans: the number of screen refreshes per second.

 

# What is Horizontal scan rate

Ans:  the total number of horizontal lines per second including blanking.

Horizontal scan rate = vertical total × Vertical frame rate

 

# How to calculate Pixel clock?

Ans:  Total number of pixels per second including blanking.

Pixel clock = horizontal total × vertical total × refresh rate