Error Messages And Error Codes; Post Progress Codes And Messages; Table 89. Post Progress Code Led Example - Intel SE7520AF2 Technical Product Specification

Intel® Server Board SE7520AF2 TPS
error handler disables further reporting of that type of error. A unique counter is used for each
type of error; i.e., an overrun of memory errors does not affect bus error reporting.
The BIOS re-enables logging and SMIs the next time the system is rebooted.
7.3

Error Messages and Error Codes

The system BIOS displays error messages on the video screen. Prior to video initialization,
beep codes inform the user of errors. POST error codes are logged in the event log. The BIOS
displays POST error messages on the video monitor. For some errors BIOS may display POST
error codes as well.
7.3.1

POST Progress Codes and Messages

7.3.1.1 System ROM BIOS POST Task Test Point (Port 80h Code)
The BIOS sends a 1-byte hex code to port 80 before each task. The port 80 codes provide a
troubleshooting method in the event of a system hang during POST. Below is the table of the
Port 80 codes and the corresponding task description.
7.3.1.2 Diagnostic LEDs
The value of port 80h will be sent to four tri-color LEDs. The diagnostic LED feature consists of
a hardware decoder and four dual color LEDs located on the baseboard. During POST, the
LEDs will display all normal POST progress codes representing the progress of the BIOS
POST. Each code will be represented by a combination of colors from the four LEDs.
The LEDs are in pairs of green and red. The POST progress codes are divided into two nibbles,
an upper nibble and a lower nibble. Each bit in the upper nibble is represented by a red LED
and each bit in the lower nibble is represented by a green LED. If both bits are set in the upper
nibble and in the lower nibble then both red and green LEDs are lit, resulting in an amber color.
If both bits are clear, then both the red and green LEDs are off.
In the below example, BIOS sends a value of ACh to the LEDs. The LEDs are decoded as
follows:
Red bits = 1010b = Ah
Green bits = 1100b = Ch
Since the red bits correspond to the upper nibble and the green bits correspond to the lower
nibble, the two are concatenated to be ACh.
LEDs Red
ACh 1
Result Amber
Revision 1.2

Table 89. POST Progress Code LED Example

Green Red Green
1 0
Green
Intel order number C77866-003
Red Green
1 1 0
Red
Error Reporting and Handling
Red Green
0 0
Off
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