74ACT715-RSC datasheet(5/14 Pages) FAIRCHILD

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FIGURE 2. Vertical Waveform Specification

FIGURE 3. Equalization/Serration Interval Programming

HORIZONTAL AND VERTICAL GATING SIGNALS

Horizontal Drive and Vertical Drive outputs can be utilized

as general purpose Gating Signals. Horizontal and Vertical

Gating Signals are available for use when Composite Sync

and Blank signals are selected and the value of Bit 2 of the

Status Register is 0. The Vertical Gating signal will change

in the same manner as that specified for the Vertical Blank.

Horizontal Gating Signal Width

= [REG(16) − REG(15)] ×

ckper

Vertical Gating Signal Width:

= [REG(18) − REG(17)] ×

hper

CURSOR POSITION AND VERTICAL INTERRUPT

The Cursor Position and Vertical Interrupt signal are avail-

able when Composite Sync and Blank signals are selected

and Bit 2 of the Status Register is set to the value of 1. The

Cursor Position generates a single pulse of n clocks wide

during every line that the cursor is specified. The signals

are generated by logically ORing (ANDing) the active LOW

(HIGH) signals specified by the registers used for generat-

ing Horizontal and Vertical Gating signals. The Vertical

Interrupt signal generates a pulse during the vertical inter-

val specified. The Vertical Interrupt signal will change in the

same manner as that specified for the Vertical Blanking sig-

nal.

Horizontal Cursor Width

= [REG(16) − REG(15)] × ckper

Vertical Cursor Width

= [REG(18) − REG(17)] × hper

Vertical Interrupt Width

= [REG(14) − REG(13)] × hper

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