PC4-PRESTO • CompactPCI
®
PlusIO • 4
th
Generation Intel
®
Core™-4xxx Processor
GP (General Purpose) LED
This programmable bicolour LED can be observed from the PC4-PRESTO front panel. The status of the
red part within the LED is controlled by the GPIO18 of the PCH QM87. 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/pc4/firmware/biosinfo.txt.
HD (Hard Disk Activity) LED
The PC4-PRESTO offers a bicoloured LED marked as HD placed within the front panel. This LED, when
blinking green, signals activity on any device attached to the SATA ports of the QM87.
The yellow part of the HD LED shows activity on any of the 88SE9230 SATA ports.
As previously described, the green part of this LED may change its function dependent on the state of
the LED PG.
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