Kontron AM4024e - Manual (Page 27)

D R A F T — F O R I N
T E R N A L U S E O N L Y
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User Guide
AM4024(E)
How to Read the 8-Bit POST Code
Due to the fact that only 4 LEDs are available and 8 bits must be displayed, the POST code output is
multiplexed on the User-Specific LEDs.
The following is an example of the User-Specific LEDs’ operation with POST configuration enabled (see
also Table 8).
Note: Under normal operating conditions, the User-Specific LEDs should not remain lit during
boot-up. They are intended to be used only for debugging purposes. In the event that a
User-Specific LED lights up during boot-up and the AM4024(E) does not boot, please con-
tact Kontron.
If all User-Specific LEDs flash red on and off at regular intervals, they indicate that the
processor junction temperature has reached a level beyond which permanent silicon dam-
age may occur. Once activated, the overtemperature event remains latched until a cold re-
start of the AM4024(E) is undertaken (all power off and then on again).
2.7.2 Module Handle
At the front panel, the AM4024(E) provides a handle for module extraction as well as for securing the
module in the carrier / chassis and actuating the hot swap switch. The module handle supports a three-
position operation.
Figure 7: Module Handle Positions
Table 8: POST Code Sequence
STATE GENERAL PURPOSE LEDs
0 All ULEDs are OFF; start of POST sequence
1 High nibble
2 Low nibble; state 2 is followed by state 0
Table 9: POST Code Example
ULED3 ULED2 ULED1 ULED0 RESULT
HIGH NIBBLE off (0) on (1) off (0) off (0) 0x4
LOW NIBBLE off (0) off (0) off (0) on (1) 0x1
POST CODE 0x41
Locked
Hot Swap
Unlocked