Functional Description
10.5.1
Analog Display Port Characteristics
The analog display port provides a RGB signal output along with a HSYNC and VSYNC
signal. There is an associated DDC signal pair that is implemented using GPIO pins
dedicated to the analog port. The intended target device is for a CRT based monitor
with a VGA connector. Display devices such as LCD panels with analog inputs may
work satisfactory but no functionality has been added to the signals to enhance that
capability.
Table 10-8. Analog Port Characteristics
Signal
Port Characteristic
Support
Voltage Range
Monitor Sense
Analog Copy Protection
Sync on Green
Voltage
0.7 V p-p only
Analog Compare
RGB
No
No
2.5 V
Enable/Disable
Polarity adjust
Composite Sync Support
Special Flat Panel Sync
Stereo Sync
Port control
HSYNC
VSYNC
VGA or port control
No
No
No
Voltage
Externally buffered to 5 V
Through GPIO interface
DDC
Control
10.5.1.1
10.5.1.2
Integrated RAMDAC
The display function contains a RAM-based Digital-to-Analog Converter (RAMDAC) that
transforms the digital data from the graphics and video subsystems to analog data for
the CRT monitor. GMCH’s integrated 400 MHz RAMDAC supports resolutions up to
2048 x 1536 @ 75 Hz. Three 8-bit DACs provide the R, G, and B signals to the
monitor.
Sync Signals
HSYNC and VSYNC signals are digital and conform to TTL signal levels at the
connector. Since these levels cannot be generated internal to the device, external
level shifting buffers are required. These signals can be polarity adjusted and
individually disabled in one of the two possible states. The sync signals should power
up disabled in the high state. No composite sync or special flat panel sync support will
be included.
Datasheet
299
INTEL [ INTEL ]
