JG82855GMESL7VN Datasheet, PDF (44/213 Pages) Intel Corporation – Intel® 855GM/855GME Chipset Graphics and Memory Controller Hub (GMCH)

Signal Descriptions
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3.6.4 Digital Video Output C (DVOC) Port
Table 15. Digital Video Output C (DVOC) Port Signal Descriptions
Name
DVOCD[11:0]
DVOCHSYNC
DVOCVSYNC
DVOCBLANK#
DVOCFLDSTL
Type
O
DVO
O
DVO
O
DVO
O
DVO
I
DVO
Description
DVOC Data: This data bus is used to drive 12-bit RGB data on each edge of the
differential clock signals, DVOCCLK and DVOCCLK#. This provides 24-bits of data per
clock period. In dual channel mode, this provides the upper 12-bits of pixel data.
DVOCD[11:0] should be left as left as NC (“Not Connected”) if not used.
Horizontal Sync: HSYNC signal for the DVOC interface.
DVOCHSYNC should be left as left as NC (“Not Connected”) if not used.
Vertical Sync: VSYNC signal for the DVOC interface.
DVOCVSYNC should be left as left as NC (“Not Connected”) if the signal is NOT used
when using internal graphics device.
Flicker Blank or Border Period Indication: DVOCBLANK# is a programmable output
pin driven by the GMCH.
When programmed as a blank period indication, this pin indicates active pixels excluding
the border. When programmed as a border period indication, this pin indicates active pixel
including the border pixels.
DVOCBLANK# should be left as left as NC (“Not Connected”) if not used.
TV Field and Flat Panel Stall Signal. This input can be programmed to be either a TV
Field input from the TV encoder or Stall input from the flat panel.
DVOC TV Field Signal: When used as a Field input, it synchronizes the overlay field with
the TV encoder field when the overlay is displaying an interleaved source.
DVOC Flat Panel Stall Signal: When used as the Stall input, it indicates that the pixel
pipeline should stall one horizontal line. The signal changes during horizontal blanking.
The panel fitting logic, when expanding the image vertically, uses this.
DVOCFLDSTL needs to be pulled down if not used.
Table 16. DVOB and DVOC Port Common Signal Descriptions
Name
DVOBCINTR#
ADDID[7:0]
DVODETECT
Type
I
DVO
I
DVO
I
DVO
Description
DVOBC Interrupt: This pin is used to signal an interrupt, typically used to indicate a hot
plug or unplug of a digital display.
ADDID[7:0]: These pins are used to communicate to the Video BIOS when an external
device is interfaced to the DVO port.
Note: Bit[7] needs to be strapped low when an on-board DVO device is present. The other
pins should be left as NC.
DVODETECT: This strapping signal indicates to the GMCH whether a DVO device is
present or not. When a DVO device is connected, then DVODETECT = 0.
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