56 AMD Geode™ SC2200 Processor Data Book
Signal Definitions
32580B
3.4.4 CRT/TFT Interface Signals
Signal Name Ball No. Type Description Mux
DDC_SCL Y1 O DDC Serial Clock. This is the serial clock for the VESA
Display Data Channel interface. It is used for monitor
communications. The DDC2B standard is supported by
this interface.
IDE_DATA10
DDC_SDA Y2 I/O DDC Serial Data. This is the bidirectional serial data sig-
nal for the VESA Display Data Channel interface. It is
used for monitor communications. The DDC2B standard
is supported by this interface.
IDE_DATA9
HSYNC A11 O Horizontal Sync ---
VSYNC B11 O Vertical Sync ---
VREF D16 I/O Volta ge R efe ren ce. Reference voltage for CRT PLL and
DAC. This signal reflects the internal voltage reference. If
internal voltage reference is used (recommended), leave
this ball disconnected. If an external voltage reference is
used, this input is tied to a 1.235V reference.
---
SETRES B15 I Set Resistor. This signal sets the current level for the
RED/GREEN/BLUE analog outputs. Typically, a 464Ω,
1% resistor is connected between this ball and AVSSCRT
.
---
On-Chip RAMDAC
RED B12 O Analog Red, Green and Blue ---
GREEN A14 ---
BLUE A15 ---
TFT (External DAC) Interface
TFTDCK AA1 O TFT Clock. Clock to external CRT DACs or TFT. IDE_RST#
A10 GPIO17+ IOCS0#
TFTDE P2 O TFT Data Enable . Can be used as blank signal to exter-
nal CRT DACs.
IDE_CS1#
B18 ACK#+FPCICLK
FP_VDD_ON AB1 O TFT Power Control. Used to enable power to the Flat
Panel display, with power sequence timing.
IDE_DATA4
V30 GXCLK+TEST3
TFTD[17:0] See
Table 3-3
on page
41.
ODigital RGB Data to TFT.
TFTD[5:0] - Connect to BLUE TFT inputs.
TFTD[11:6] - Connect to GREEN TFT inputs.
TFTD[17:12] - Connect to RED TFT inputs.
The TFT interface is
muxed with the IDE
interface or the Par-
allel Port. See Table
3-5 on page 46 and
Table 3-6 on page
48 for details.
3.4.5 ACCESS.bus Interface Signals
Signal Name Ball No. Type Description Mux
AB1C N31 I/O ACCESS.bus 1 Serial Clock. This is the serial clock for
the interface.
Note: If selected as AB1C function but not used, tie
AB1C high.
GPIO20+DOCCS#