DIGITAL-LOGIC SM800/900DK, Technical User'S Manual

Page: 67 / 103

DIGITAL-LOGIC AG
SM800/900DK Technical Manual V1.2B
67
13.1. Start up/Power off Procedure
VCCSB = VCCSUS must be present in order to start the SM800/900PC/X. By factory default the
SM800/900PC/X automatically powers-on by setting the SUSC# signal low and requesting the base board to
turn on the main power supply.
13.1.1. AUTOSTART Mode (Default)
AUTOStart Mode: system starts automatically with the VCC5SB
X200A-Pin-A43 is open (internal pulldown resistor to GND)
= Autostart with VCC5SB=5Volt
13.1.2. ATX-START Mode
ATX-Start Mode: the PWRBTN# must be activated by pulling to GND for a system start.
X200A-Pin-43 is connected to VCC5SB with 1kOhms
= ATX-Start Mode: system waits until the signal PWRBTN# is actived by pulling down
While running, the module can be turned off either by the operating system or by issuing a low pulse of at
least 4000ms on the PWRPTN (forced shut down). When the power button is pressed for at least 300ms
while running, this event passes through to the GEODE chip.
An ACPI compliant operating system then shuts down, if configured to do so. When the GEODE chip
indicates that it has turned off, the SUSC# signal will go high, thus turning off the main power supply on the
base board.