6.7.2. Timing Control

Try these first

1. 1.

   What does HSYNC control?

   Hint

   Think about what happens at the end of a row of pixels.

2. 2.

   Define VSYNC.

   Hint

   Consider what happens when the whole screen refreshes.

3. 3.

   What does HSYNC control?

   • The start of a new frame
   • The start of a new row
   • The duration of a refresh

   Hint

   Consider what happens in a line scan.

4. 4.

   Is VSYNC responsible for timing the refresh cycles of the screen?

   • True
   • False

   Hint

   It relates directly to frame refresh timing.

5. 5.

   A new monitor specification states HSYNC must be set to 64 microseconds and the front porch to 10 microseconds. Calculate the total time for one horizontal scan line including back porch if the back porch is set to 20 microseconds.

   Hint

   Remember to add all the time periods involved in one cycle.

6. 6.

   If a VGA output supports a vertical refresh rate of 60 Hz, what is the duration needed for one complete frame refresh, and how does this relate to VSYNC?

   Hint

   Consider how refresh rate dictates the timing of gegraphics output.