NT68520XF Datasheet, PDF (16/97 Pages) List of Unclassifed Manufacturers – XGA,SXGA Flat Panel Monitor Controller

NT68520X,E
Divider
The 11-bit value of Divider supports division ratios from 1 to 2048. The higher the value
loaded in this register, the higher is the resulting clock frequency with respect to a fixed
Hsync frequency. Users should program the corrective Divider value with respect to the
incoming video frequency. An incorrectly set Divider value will usually produce one or
more vertical noise bars on the display. The greater the error, the greater the number of
bars produced.
CKEXT
This pin may be used to provide an external clock to the internal ADC in place of the
clock internally generated from Hsync. When an external clock is used, all other internal
functions are operated normally. When unused, this pin should be tied through a 10K
resistor to ground.
COAST
This input is used to stop the pixel clock generator synchronizing with Hsync and
continue producing a clock at its current frequency and phase. This is useful when
processing composite sync that fails to produce horizontal sync pulses in the vertical
interval.
Analog-to-Digital Converter
The ADC is 8-bit resolution for each R/G/B channel and maximum clock frequency is 135
MHz. The ADC’s input range is 1V(p-p) full-scale.
There is one over-range bit for each channel (ROR、GOR and BOR). It will be set to ‘1’
when the signal is over the ADC’s full-scale range.
There is one under-range bit for each channel (RUR、GUR and BUR). It will be set to ‘1’
when the signal is under the ADC’s black level.
The phase adjustment for R/G/B as the same time to ensure signal is correctly sampled
by sampling clock.
CAPTURE INTERFACE
The function of Capture Interface is to provide the interface between NT68520 and
external input devices. It can process non-interlaced and interlaced RGB graphic input
and digital YUV video input. It also contains the built-in YUV to RGB color space
converter.
Users should select the video input source (YUV or VGA) and the polarity of external
control signal, then program the H/V to capture size registers to indicate the display
area.
Auto Tune
Auto Tune function includes Auto Gain, Auto Position, and Auto Phase. With such auto
2003/4/15
16
Ver.1.0