Agilent Technologies 54853A, Service Manual, Page: 121 / 194

Chapter 5: Troubleshooting
POST Code Listing
5–19
POST Code Listing
8VHWKHIROORZLQJOLVWLQJWRWURXEOHVKRRWWKHPRWKHUERDUG<RXZLOOQHHGD32673RZHU2Q
6HOI7HVWFDUGLQVWDOOHGLQDQ3&,VORWWRXVHWKLVOLVWLQJ
POST Code Listing
Checkpoint
Code DEscription
CF Test CMOS read/write functionality
C0 Early Chipset Initialization. Disable Shadow RAM; Program basic chipset registers.
C1 Memory Detect.
C3 Expand the compressed BIOS code to DRAM.
C5 Use chipset hook to copy BIOS back to shadow RAM in E000 & F000.
01 Expand the Xgroup codes located in physical address 1000:0.
03 Initialize Superio_Early_Init switch
05 Blank out the screen and clear CMOs error flag.
07 Clear 8042 interface and Initialize 8042 self-test.
08 Test keyboard controller for Winbond 977 series Super I/O chips and enable keyboard interface.
0A Disable PS/2 mouse interface (optional). Auto detect mouse and keyboard ports. Reset Keyboard
for Winbond 977 series Super I/O chips.
0E Test F000 segment shadow to see if it is R/W-able or not. If test fails the speaker will keep beeping.
10 Auto detect flash type to load appropriate flash R/W codes into the runtime area in F000 for EscD
& DMI support.
12 Use walking 1’s algorithm to check out the interface in CMOS circuitry. Set real time clock power
status, and then check for override.
14 Program chipset default values into chipset. Chipset default values are MODBINable by OEM
customers.
16 Initialize Early_Init_onboard_generator switch.
18 Detect CPU information.
1B Initialize interrupts vector table.
1D Initialize Early_PM_Init switch.
1F Load keyboard matrix (notebook only).
21 Initialize HPM (notebooks only).
23 Check validity of RTC value. Load CMOS setting into BIOS stack. If CMOS checksum fails use
default values. Prepare BIOS resource map for PCI and PnP use. Onboard clock generator
initialized. Early PCI initialization.
27 Initialize Int 09 buffer.
29 Program CPU internal MTRR for 0-640K memory address. Initialize the APIC for pentium class CPU.
Measure CPU speed. Invoke video BIOS.
2D Initialize multi language. Put information on screen display, including Award title, CPU type and
speed.
33 Reset keyboard except Winbond 977 series Super I/O chips.
3C Test 8254.