User Guide • PC3-ALLEGRO • CompactPCI
®
PlusIO CPU Board • Intel® i7-3xxx Processor
PG (Power Good) LED
The PC3-ALLEGRO offers a bicolour LED labelled PG located within the front panel. After system reset,
this LED defaults to signal different power states:
<
Off
Sleep state S3, S4 or S5
<
Green
Healthy
<
Yellow blink Front panel handle open
<
Red steady
Hardware failure
<
Red blink
Software failure
To enter the PG LED state
Software Failure,
the bit PGLED in the board control register CTRLL_REG
must be set. The PG LED remains in this red blinking state until this bit is cleared. After that it falls
back to its default function.
GP (General Purpose) LED
This programmable bicolour LED can be observed from the PC3-ALLEGRO front panel. The status of
the red part within the LED is controlled by the GPIO18 of the PCH QM77. Setting GPIO18 to “1" will
switch on the red LED. Turning on or off the green LED is done by setting the bit GPLED in the board
control register CTRLH_REG.
The GP LED is not dedicated to any particular hardware or firmware function with exception of special
power states of the LED PG as described above. Nevertheless, a red blinking GP LED is an indication
that the BIOS code couldn't start.
While the CPU card is controlled by the BIOS firmware, the GP LED is used to signal board status
information during POST (Power On Self Test). After successful operating system boot, the GP LED
may be freely used by customer software. For details please refer to
www.ekf.com/p/pc3/firmware/biosinfo.txt.
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