HP D315 manual Memory Detection and Configuration, Boot Error Codes, Visual Audible Meaning

Chapter 8 System BIOS

8.3.3 MEMORY DETECTION AND CONFIGURATION

This system uses the Serial Presence Detect (SPD) method of determining the installed DIMM configuration. The BIOS communicates with an EEPROM on each DIMM through the SMBus to obtain data on the following DIMM parameters:

♦Presence

♦Size

♦Type

♦Timing/CAS latency

♦Memory speed

NOTE: Refer to Chapter 3, “Processor/Memory Subsystem” for the SPD format and DIMM data specific to this system.

The BIOS performs memory detection and configuration with the following steps:

1.Program the buffer strength control registers based on SPD data and the DIMM slots that are populated.

2.Determine the common CAS latency that can be supported by the DIMMs.

3.Determine the memory size for each DIMM and program the graphics controller accordingly.

4.Enable refresh

5.Determine if the memory configuration will allow for double-clocked 133-MHz memory operation and program the memory clock and IGP (see note below)

NOTE: The BIOS must read a value of 07h (indicating DDR) from SPD byte 02h of each DIMM in order to validate the memory.

8.3.4 BOOT ERROR CODES

The BIOS provides visual and audible indications of a failed system boot by using the keyboard LEDs and the system speaker. The error conditions are listed in the following table.

Table 8-2.Boot Error Codes

Visual [1]	Audible	Meaning
Num Lock LED blinks	1 short, 2 long beeps	System memory not present or incompatible.
Scroll Lock LED blinks	2 long, 1 short beeps	Hardware failure before graphics initialization.
Caps Lock LED blinks	1 long, 2 short beeps	Graphics controller not present or failed to
		initialize.
Num, Caps, Scroll Lock LEDs	1 long, 3 short beeps	ROM failure.
blink
Num, Caps, Scroll Lock LEDs	none	Network service mode
blink in sequence

NOTE:

[1] Provided with PS/2 keyboard only.

8-4Compaq D315 and hp d325 Personal Computers

Featuring the AMD Athlon XP Processor

Second Edition - April 2003