Ampro Corporation COM 830 - Manual (Page 39)

Chapter 3 Signals and Pinout Tables
COM 830 Reference Manual 33
TV_DAC_B TVDAC Channel B Output supports the
following: Composite video: not used
Component video: Luminance (Y) analog
signal.
S-Video: Luminance analog signal.
O
Analog
PD 150R Analog
output
TV_DAC_C TVDAC Channel C Output supports the
following: Composite video: not used
Component: Chrominance (Pr) analog
signal.
S-Video: Chrominance analog signal.
O
Analog
PD 150R Analog
output
Table 3-12. Miscellaneous Signal Descriptions
Signal Description I/O PU/PD Comment
I2C_CK General purpose I²C port clock output O 3.3V PU 4k7
3.3V
I2C_DAT General purpose I²C port data I/O line I/O
3.3V PU 4k7
3.3V
SPKR Output for audio enunciator, the "speaker" in
PC-AT systems O 3.3V SPEAKER
is a boot
strap signal
(see note 1
below)
BIOS_DISABLE
# Module BIOS disable input. Pull low to disable
module BIOS. Used to allow off-module BIOS
implementations. I 3.3V PU 4k7
3.3V
WDT Output indicating that a watchdog time-out
event has occurred. I 3.3V PU 10k
3.3V This signal
is not
supported
(see note 2
below)
KBD_RST# Input to module from (optional) external
keyboard controller that can force a reset.
Pulled high on the module. This is a legacy
artifact of the PC-AT. I PU 10k
3.3V
KBD_A20GATE Input to module from (optional) external
keyboard controller that can be used to control
the CPU A20 gate line. The A20GATE restricts
the memory access to the bottom megabyte and
is a legacy artifact of the PC-AT. Pulled low on
the module. I PU 10k
3.3V
NOTE Some signals have special functionality during the reset process. They may
bootstrap some basic important functions of the module.
For more information about this signal, please visit Ask an Expert on the Ampro
web site.
Table 3-11. TV-Out Signal Descriptions (Continued)