The eSPI POST Code Card is a tool which monitors the eSPI bus and performs the functions:

  • display the Post codes (port 80 and port 81)
  • output Post codes to the serial port (port 80 up to port 83)
  • Distinguish byte access to port 80, 81, 82, 83 and word access to port 80 and 82 

A valuable tool for bringing-up new hardware design and debugging the BIOS of the x86 design.

Debug adapter for BIOS Development:

The BIOS firmware includes reporting POST (Power On Self Test) codes, previously output on the ISA, EISA, LPC or PCI interface. Latest x86 architecture chipsets are using the eSPI interface, starting Intel Ice Lake Platform the legacy LPC interface is even completely removed from silicon. 

The Eltan eSPI POST code card monitors the eSPI signals between the eSPI Master (the chipset) and an eSPI slave (BMC chip, eSPI embedded controller, or Super IO chip) on the main board. 

In case the main board already has an eSPI slave chip onboard then detach the small top eSPI slave board from the eSPI POST Card. 


The eSPI POST Code Card can be connected to the system using the eSPI header (2x10 pins 0.1"pitch). 

The card includes the following functions:

  • Port 80 and 81 display (can be rotated depending on the position of the board)
  • Port 80 to 83 output to the serial port (including time stamp function)
  • USB to serial converter so no serial port is required on the host system


The human eye might miss a quick update of the port 80 display, the output to the serial interface enables to view the complete sequence of all port 80-83 debug codes.

The board can be used for the following applications:

  • Port 80 code display
  • Debugging x86 PC computer board
  • Kernel debugging for any operating system
  • Output of debugging messages for UEFI BIOS and coreboot development
  • PC computer repair tool
  • Functional test tool

When required custom versions can be created to suit the needs of the customer.

More information can be found in the datasheet: Datasheet eSPI POST Code Card.  More information about the eSPI header is available at Eltan.

The eSPI POST Code Card is working on all x86 platforms using eSPI interface, the following platforms have been verified:


  • Alder Lake
  • Comet Lake
  • Elkhart Lake
  • Kaby Lake
  • Skylake
  • Tiger Lake
  • Whiskey Lake

More information about the eSPI header is available at Eltan.


  • AMD Lilac board: Contact Eltan if you want to connect eSPI POST Card with the eSPI connector: ec_j1 . 

Please return soon to this page, this list is crowing rapidly. 


Background information

During the POST Power on self test the BIOS and also other boot loaders like and slim-bootloader output debug code to port 80, which might be displayed by POST card.  Also firmware using the Unified Extensible Firmware interface are using POST codes. Using UEFI is Operating System independent. Most reference boards by Intel and AMD have an eSPI header. Developers of (laptop, desktop) boards can include the eSPI header for board-debugging purposes, and it might be used by board manufacturers for assembly test and it is very help full repairing boards. 

Like mentioned eSPI POST Code Card works on all platforms supporting eSPI, which is supported by all the latest Intel chipsets, starting Skylake and mandatory starting Ice Lake. So eSPI POST Code Card works on all corresponding processors:

  • Intel® Xeon® Processors
  • Intel® Core™ Processors
  • Intel® Pentium® Processors
  • Intel® Celeron® Processor 
  • Intel Atom® Processors








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