Digital Sync Parameters

Some analog video and all digital video displays require one or two digital sync signals. The paramters associated with these signals can be found at the top of the right-hand column of the format work- sheet.

If your display accepts separate horizontal and ver- tical digital sync signals, you should set the DSST parameter to the exact type that is needed. A set- ting of zero (0) means that separate horizontal and vertical digital sync cannot be selected.

The polarity of the separate horizontal sync output is controlled by the HSPP parameter, while the po- larity of the separate vertical sync output is con- trolled by the VSPP parameter.

Entering the wrong HSPP polarity may cause all of the test images to be shifted horizontally on a properly adjusted display. Entering the wrong VSPP polarity may cause all of the test images to be shifted vertically on a properly adjusted display.

Also, many multi-scan mode displays depend on the polarity of the sync pulses to determine their exact operating mode. The wrong polarities may prevent the display from locking to the format’s scan rates or may cause the size of the active video to be way off.

If your display accepts a single combined digital sync input, you should set the DSCT parameter to the exact type that is needed. A setting of zero (0) means that digital composite sync cannot be selected.

The polarity of the digital composite sync output is controlled by the CSPP parameter.

You have now defined the type of video and sync that will be generated when your new format is selected. Next, you will specify the timing of the various signal components.

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Quantum Data 801GC, 801GF, 801GX manual Digital Sync Parameters