home search worldwide Acer.EMEA
About Acer Drivers & Utilities FAQ's Documents Contact Acer
EMEA Support
Welcome
About Acer
Drivers & Utilities
Technical FAQ's
Technical Documents
Manuals & Guides
Product Certificates
How To guides
Contact Acer
Microsoft Windows Help
Copyright © 2001-2005
Acer Corporation
All Rights Reserved.
Legal Notices
and Trademarks
Stepping Code Update

Stepping Code Update
Question:
After the installation of a new CPU the system starts with an error message such as:
CPU BIOS UPDATE CODE MISMATCH or BU CODE MISMATCH and Equipment Configuration Error.

Clarification:
Every Pentium II or III CPU (Codename Klamath, Katmai, Coppermine etc) or Pentium Pro Generation CPU contains so-called "stepping" (type identifier) value which is set during manufacture. This stepping information is verified by the BIOS against a stored list during system start. If the CPU is changed the new values must be set in the BIOS (or the BIOS values must be updated) if the CPU is not present on the current lists.

Answer:
Each BIOS Version contains stepping codes for different CPU Types. If you upgrade a PC or Server with a new CPU you may get the above error message. This means the stepping code for the new CPU is not included in your current BIOS Version. In this case it is recommended to update your System BIOS.

By flashing your motherboard, you agree to accept the possibility of BIOS flash failure. If you intent to upgrade the BIOS, PLEASE BE SURE to use the right BIOS revision for the right motherboard model.

If you still get the BIOS UPDATE CODE MISMATCH message after updating to the latest BIOS Version for you System, you need to update the stepping seperatly.
To match the CPU stepping data and the data stored in the BIOS a CPU stepping update should be performed.

Note: The stepping code update can damage your system if you have not the latest BIOS Version installed.

  1. Start the system without drivers (DOS boot diskette) and run the BU code update program.
  2. The program will display the stepping data and ID for your CPU (value in brackets).
  3. Identify the source code file that contains the correct, matching steppings and values for your CPU (the attached pdb file contains most stepping codes)
  4. Run the program Chekup6.exe with the parameter call to the correct source file as shown in the following example:
    eg. For Example : checkup6 -p per_p_10.pdb

After the update, and a full re-start of your system, all settings will be correct and the error messgae will no longer be shown.

Download the Stepping update tool
(BIOS Update Tools, Stepping Code update)

Top of Page