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Configuration
4.3.14
Debug LED Configuration Register (DLCFG)
The Debug LED Configuration Register holds a series of bits defining the onboard configuration
of the onboard debug LEDs (DLED 0..3). For the location of the debug LEDs, refer to Figure 1-4.
Table 4-19: Debug LED Configuration Register (DLCFG)
REGISTER NAME
ADDRESS
BIT
NAME
7-4
Res.
Reserved
3-0
DLCON
Debug LED Configuration
0000 = POST
0001 = Mode A (General Purpose Mode)
0010 = Mode B
0011 - 1111 = Reserved
1)
In uEFI BIOS POST mode, the Debug LEDs build a binary vector to display uEFI BIOS POST
code during the pre-boot phase. In doing so, the higher 4-bit nibble of the 8-bit uEFI BIOS
POST code is displayed followed by the lower nibble followed by a pause. uEFI BIOS POST
code is displayed in general in green color.
DLED3:
POST bit 3 and bit 7 (green)
DLED2:
POST bit 2 and bit 6 (green)
DLED1:
POST bit 1 and bit 5 (green)
DLED0:
POST bit 0 and bit 4 (green)
2)
Configured for Mode A (General Purpose Mode), the Debug LEDs are dedicated to functions
as follows:
DLED3:
Debug LED 3, controlled by host (green/red)
DLED2:
Debug LED 2, controlled by host (green/red)
DLED1:
Debug LED 1, controlled by host (green/red)
DLED0:
Debug LED 0, controlled by host (green/red)
3)
Configured for Mode B, the Debug LEDs are dedicated to functions as follows:
DLED3:
Gigabit Ethernet port D link status (green)
DLED2:
Gigabit Ethernet port C link status (green)
DLED1:
Gigabit Ethernet port B link status (green)
DLED0:
Gigabit Ethernet port A link status (green)
Beside the configurable functions described above, the Debug LEDs fulfill also a basic debug
function during the power-up phase as long as the first access to Port 80 is processed. If an
LED lights red and stays red, than a basic error is present on the board. The following debug
functions are defined and displayed during this initialization phase.
DLED3:
PGOOD, Power Good status not reached (red)
DLED2:
CPU catastrophic error (red)
DLED1:
RST, PCI reset active / not deactivated (red)
DLED0:
uEFI BIOS boot failure (red)
Page 4 - 16
DEBUG LED CONFIGURATION REGISTER (DLCFG)
DESCRIPTION
1)
3)
CP3002-RC/CP3002-RA
0x290
2)
ID 1039-3625, Rev. 1.0
RESET
ACCESS
VALUE
0000
R
0001
R/W
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