SPC8106 S-MOS Systems, SPC8106 Datasheet - Page 417

• Manufacturer Part Number: SPC8106
• Description: LCD/CRT VGA CONTROLLER
• Manufacturer: S-MOS Systems

The RAMDAC requires a voltage reference to provide the necessary DAC output gain. This volt-
age reference can be provided internally or externally. Using the external voltage reference pro-
vides a more accurate, more stable, and less noisy voltage source. When the RAMDAC is in
Sleep Mode, the Vref pin is disabled and does not use any power. Although the SPC8106 does
provide a control pin, /IREFEN, it is not required by this design.
The ATT20C497 has been provided with an external voltage reference.
3.7
The SDU8106B0F evaluation board is capable of directly supporting the VESA DDC2B monitor
standard. This board supports hardware DDC2B and the BIOS supports software layer VBE/DDC
version 1.0. For further information on DDC2B contact the Video Electronics Standards Asocia-
tion (VESA).
3.8
A 32K EPROM contains the VGA BIOS. Support logic consists of an Address Decoder (C000h-
C7FFh) and a Data Buffer. With the BIOS installed, the board will operate as a stand-alone video
adapter.
3.9
The various power save modes can be controlled via software or hardware. A separate software
utility is supplied to control power save modes. See PWRSAVE Power Save Utility, Drawing Office
No. X12-UI-004-xx for more information.
Hardware SUSPEND mode is not supported in this design.
3.10 Adjustable LCD Panel Positive Power Supply(VDDH)
Most color STN LCD panels require a positive power supply VDDH between +23V and +40V
(I
part of this design. The VDDH voltage can be found on LCD connector(J6) at pin 34. The VDDH
voltage can be varied by R43(200K potentiometer) and controlled by LCDPWR# signal.
R43 can be adjusted to provide an output voltage between +23V and +40V.
LCDPWR# is a control signal provided by the SPC8106 to enable/disable the VDDH power sup-
ply. This signal provides correct power sequencing and prevents panel damage.
Adjust VDDH voltage to the appropriate voltage required by the panel before connecting the
panel.
3.11 Adjustable LCD Panel Negative Power Supply(VLCD)
Most monochrome STN LCD panels require a negative power supply VLCD between -18V and -
23V (Iout=45 mA). For ease of implementation, such a power supply has been provided as an
integral part of this design. The VLCD voltage can be found on LCD connector(J6) at pin 32. The
VLCD voltage can be varied R45(100K potentiometer) and controlled by LCDPWR# signal.
R45 can be adjusted to provide an output voltage between -18V and -23V.
LCDPWR# is a control signal provided by the SPC8106 to enable/disable the VLCD power sup-
ply. This signal provides correct power sequencing and prevents panel damage.
Adjust VLCD to the appropriate voltage required by the panel before connecting the panel.
SPC8106
out
411-1.0
=45 mA). For ease of implementation, such a power supply has been provided as an integral
DDC2B Support
VGA BIOS Support
Power Save Modes
S-MOS Systems, Inc. • Tel: [phone] • Fax: [phone] • http://www.smos.com
X12-AN-005-02
SDU8106B
0F
Rev. 1.0 Evaluation Board User Manual
EV2-15