Intel® Core™ Ultra 200S, Intel® Core™ Ultra 200S Plus ,Intel® Core™ Ultra 200HX and 200HX Plus Series Processors

Datasheet, Volume 1 of 2

ID Date Version Classification
832586 03/17/2026 Public
Document Table of Contents
LAM

Port 80h Decode

The PCIe* root ports will explicitly decode and claim I/O cycles within the 80h – 8Fh range when MPC.P8XDE is set. The claiming of these cycles are not subjected to standard PCI I/O Base/Limit and I/O Space Enable fields. This allows a POST-card to be connected to the Root Port either directly as a PCI Express* device or through a PCI Express* to PCI bridge as a PCI card.

Any I/O reads or writes will be forwarded to the link as it is. The device will need to be able to return the previously written value, on I/O read to these ranges. BIOS must ensure that at any one time, no more than one Root Port is enabled to claim Port 80h cycles.