STPCI2 STMicroelectronics, STPCI2 Datasheet - Page 87

• Manufacturer Part Number: STPCI2
• Description: STPC ATLAS DATASHEET - X86 CORE PC COMPATIBLE SYS
• Manufacturer: STMicroelectronics

6.3.9. VGA INTERFACE
The STPC integrates a voltage reference and
video buffers. The amount of external devices is
then limited to the minimum as described in the
Figure
All the resistors and capacitors have to be as
close as possible to the STPC while the circuit
protector DALC112S1 must be close to the VGA
connector.
The DDC[1:0] lines, not represented here, have
also to be protected when they are used on the
VGA connector.
6-15.
VREF_DAC
VDD_DAC
VSS_DAC
COL_SEL
HSYNC
VSYNC
COMP
DCLK
RSET
Figure 6-15. Typical VGA implementation
G
R
B
143
Issue 1.0 - July 24, 2002
1%
10nF
75 1%
100nF
COL_SEL can be used when implementing the
Picture-In-Picture function outside the STPC, for
example when multiplexing an analog video
source. In that case, the CRTC of the STPC has to
be genlocked to this analog source.
DCLK is usually used by the TFT display which
has RGB inputs in order to synchronise the picture
at the level of the pixel.
When the VGA interface is not needed, the signals
R, G, B, HSYNC, VSYNC, COMP, RSET can be
left unconnected, VSS_DAC and VDD_DAC must
then be connected to GND.
100nF 47uF
DALC112S1
3.3V
AGND
AGND
2.5V
DESIGN GUIDELINES
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