User guide

Using the System
15
Figure 3.5 VGA Display Horizontal timing spec
 Both Horizontal and Vertical timing periods can be divided into four zones:
H-Sync (a), back porch (b), front porch (d), and display interval(c).
 Refer to Figure 3.6 for detailed VGA timing spec on the four timing zones.
 Refer to Table 3.1 for the pin assignment of the associated interface.
VGA mode Horizontal Timing Spec
Configuration Resolution(HxV) a(us) b(us) c(us) d(us) Pixel clock(Mhz)
VGA(60Hz) 640x480 3.8 1.9 25.4 0.6 25 (640/c)
VGA(85Hz) 640x480 1.6 2.2 17.8 1.6 36 (640/c)
SVGA(60Hz) 800x600 3.2 2.2 20 1 40 (800/c)
SVGA(75Hz) 800x600 1.6 3.2 16.2 0.3 49 (800/c)
SVGA(85Hz) 800x600 1.1 2.7 14.2 0.6 56 (800/c)
XGA(60Hz) 1024x768 2.1 2.5 15.8 0.4 65 (1024/c)
XGA(70Hz) 1024x768 1.8 1.9 13.7 0.3 75 (1024/c)
XGA(85Hz) 1024x768 1.0 2.2 10.8 0.5 95 (1024/c)
1280x1024(60Hz) 1280x1024 1.0 2.3 11.9 0.4 108 (1280/c)
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VGA mode Vertical Timing Spec
Configuration Resolution(HxV) a(lines) b(lines) c(lines) d(lines)
VGA(60Hz) 640x480 2 33 480 10
VGA(85Hz) 640x480 3 25 480 1
SVGA(60Hz) 800x600 4 23 600 1
SVGA(75Hz) 800x600 3 21 600 1
SVGA(85Hz) 800x600 3 27 600 1
XGA(60Hz) 1024x768 6 29 768 3
XGA(70Hz) 1024x768 6 29 768 3
XGA(85Hz) 1024x768 3 36 768 1
1280x1024(60Hz) 1280x1024 3 38 1024 1
Figure 3.6 VGA Display Detailed Timing Spec