Planar LC1200R user manual Mode Detection, Color Display Detection, TTL Sync Pulse Signal Levels

4.2.3 Mode Detection

The polarity of incoming horizontal/vertical frequencies and synchronization pulses define the video resolution being presented. Video modes are listed in Table 5 Video Mode Definitions.

Table 5 Video Mode Definitions

Video Mode	Displayed	Scanning		Sync Polarity
	Image	Frequency)
	Resolution
		Horizon	Vertical	Horizont	Vertic
		tal (KHz)	(Hz)	al	al
IBM VGA	640 x 400	31.468	70	-	+
IBM VGA	640 x 480	31.468	60	-	-
IBM VGA	656 x 496	31.468	60	-
w/Border					-
IBM VGA	720 x 400	31.468	70	-	-
IBM VGA	738 x 414	31.468	70
w/Border
VESA	800 x 600	48.077	72	+	+
VESA	1024 x 768	56.48	70	-	-

4.2.4 Color Display Detection

The video signal source determines which type of display is connected to it based on the state of the LC1200R sense lines. The LC1200R will indicate to the source that it is a "color display" when the monitor sense line 1 (Pin 11) is physically connected to signal ground reference (Pin 10) as defined by the wiring definitions ofTable 4 Video Signal Connector – Pin Number Assignments.

4.3Signal Quality

4.3.1TTL Sync Pulse Signal Levels

Input levels for the horizontal and vertical sync pulses are defined in Figure 5.

4.3.2 Rise and Fall Times

Rise and fall times are the times required for signal transitions between 10% of Vs above low steady level and 10% of Vs below high steady level where Vs is the peak-to-peak video input signal level. The overshoot, if present, shall be exempted from establishing these high/low levels referenced in. Both rise and fall times of each input signal shall be as follows:

Video:	Less than 5-ns
Horizontal Sync:	Less than 50-ns
Vertical Sync:	Less than 100-ns

LC1200R User’s Guide 021-0183-00 Rev A 14 of 29