ADLINK Technology COM Express Type 7 Starter Kit Plus, Quick Start Manual, Page: 23 / 26

Type 7 Starter Kit Plus
Debug Card
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5.3. Display and LEDs
This section describes the hexadecimal display and LED functionality.
5.3.1. Bootup Procedure
During power-up and BIOS execution the CPU will first retrieve commands from POST and then execute them.
Each command has a corresponding debug port data code or BIOS POST checkpoint code. The results from each
checkpoint can be viewed on the DB40 Debug Card’s LED display, allowing the techinican or administrator to
debug the system. The POST code is written to I/O port 80h, and for extended POST codes port 80h and 81h are
used.
The POST code is shown on the two 7-segment LED displays on the board
5.3.2. LED Table
The following LEDs indicate status of system signals as shown in the table below.
LED Function
CB_RESET# LED lights on active reset signal of carrier board
CB_PWROK LED lights on active power-OK from COM Express module
SUS_S3# LED lights on released SUS_S3# signal from COM Express module
SUS_S4# LED lights on released SUS_S4# signal from COM Express module
SUS_S5# LED lights on released SUS_S5# signal from COM Express module
BMC_STATUS LED shows the status of the BMC on the COM Express module
PWRBTN# LED lights on active power button signal of COM Express module
SYS_RESET# LED lights on active reset signal of COM Express module
5.3.3. BMC Status
The BMC_STATUS LED shows the status of the BMC on the COM Express module.
Behavior (blue) Description
Blinking A blinking BMC_STATUS LED indicates a failure during power up. The
number of flashes indicates the error code. A missing/wrong system voltage,
stuck on the reset line, BIOS failure or an unexpected shutdown of an
onboard power supply is displayed by this signaling code. The error code is
board specific (refer to the user’s manual for your COM Express module).
Bright flash A system state change occurs. Power-button activity, Reset-button activity,
PCI_RST# activity or activity on the SLP_Sx signals is shown by this
signaling mode.
Fast blinking If the board is running on Fail-Safe-BIOS, the BMC_STATUS LED blinks
very quickly.
Short bright flash
every 4 seconds System is in Suspend-to-RAM or Suspend-to-Disk state.