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To turn the LED on and off, set or clear bit D7 in I/O port CA0h. When changing the register,
make sure not to alter the value of the other bits.
The following code examples show how to turn the LED on and off.
LED On
MOV
DX,CA0H
IN
AL,DX
OR
AL,80H
OUT
DX,AL
P
LED
OWER
The power LED on the VL-CBR-5013 indicates that the paddle board is being powered by the
5V supply (though it does not indicate that all S0 power supplies are good). The LED is lit only
on when the board is in the S0 power state. If the board enters a Sleep or Hibernate mode, the
LED will not be lit.
There is also an on-board green "Power-OK" LED (at location D10). This will illuminate when
all power rails are good, and indicates that the board is in the S0 power state. If any power rail is
not good, the LED will not illuminate. It also goes out when the board enters a sleep or hibernate
power mode.
Pushbutton Reset
Connector J29 includes an input for a pushbutton reset switch. Shorting J29 pin 40 to ground
causes the Copperhead to reboot.
The input can be connected to ground using the normally open contacts of a pushbutton switch or
a relay, or with a switching transistor (open-collector or open-drain) capable of sinking 1 mA.
The input must be driven to a voltage between 0V and 500mV to be recognized by the
Copperhead. Do not add an external pull-up resistor to this signal.
This connector uses IEC 61000-4-2-rated TVS components to help protect against ESD damage.
A reset button is provided on the VL-CBR-5013 breakout board. Terminal block J8 on the
breakout board also provides a reset signal on pin 1 and ground on pin 2.
Power Button
Connector J19 includes an input for a power button. Shorting J19 pin 41 to ground causes the
board to enter an S5 power state (similar to the Windows Shutdown state). Shorting it again will
return the board to the S0 power state and reboot the board. The button can be configured in
Windows to enter an S3 power state (Sleep, Standby, or Suspend-to-RAM), an S4 power state
(Hibernate or Suspend-to-Disk), or an S5 power state (Shutdown or Soft-Off).
This connector uses IEC 61000-4-2-rated TVS components to help protect against ESD damage.
A power button is provided on the VL-CBR-5013 breakout board. Terminal block J8 also
provides a power button signal on pin 3 and ground on pin 2.
In configurations where a power button is not connected to the board, if the system is put into an
S5 state, power can be restored by turning off the power supply and turning it back on. This
behavior is set by default by the BIOS. The behavior can be changed using the Restore AC
Power Loss parameter on the Chipset > South Bridge menu of the BIOS setup screens.
EBX-41 Reference Manual
LED Off
MOV
DX,CA0H
IN
AL,DX
AND
AL,7FH
OUT
DX,AL
Interfaces and Connectors
50
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