Intel SE7221BK1-E manual Diagnostic LEDs, Diagnostic LED Post Progress Codes

SE7221BK1-ETechnical Product Specification

9.8Diagnostic LEDs

All port 80 codes are displayed using the Diagnostic LEDs found on the back edge of the baseboard. The diagnostic LED feature consists of a hardware decoder and four dual color LEDs. During POST, the LEDs will display all normal POST 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 capable of displaying three colors: Green, Red, and Amber. The POST 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 and lower nibbles then both Red and Green LEDs are lit, resulting in an Amber color. If both bits are clear, then the LED is off.

In the below example, BIOS sends a value of ACh to the Diagnostic LED decoder. The LEDs are decoded as follows:

ƒRed bits = 1010b = Ah

ƒGreen 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.

Table 75. POST Progress Code LED Example

LEDs

Ach

Result

Red		Green	Red	Green	Red	Green	Red		Green
1		1	0	1	1	0	0		0
Amber			Green		Red		Off
	MSB							LSB

9.8.1Diagnostic LED POST Progress Codes

							Table 76. Boot Block POST Progress Codes
			Diagnostic LED					Description
				Decoder
		G=Green, R=Red,
				A=Amber
		Hi				Low
	10h	Off		Off	Off	R		The NMI is disabled. Start Power-on delay. Initialization code checksum
								verified.
	11h	Off		Off	Off	A		Initialize the DMA controller, perform the keyboard controller BAT test, start
								memory refresh, and enter 4 GB flat mode.
	12h	Off		Off	G	R		Get start of initialization code and check BIOS header.
	13h	Off		Off	G	A		Memory sizing.
	14h	Off		G	Off	R		Test base 512K of memory. Return to real mode. Execute any OEM patches
								and set up the stack.
64								Revision 1.3