Intel® 800 Series Chipset Family Platform Controller Hub (PCH)

Datasheet, Volume 1 of 2

ID Date Version Classification
833778 01/07/2025 Public
Document Table of Contents

PCH eSPI Switch

The eSPI switch decodes and routes the eSPI cycles among the following agents:

Peripheral Channel:

  • PCH Direct eSPI controller
    • EC/PCH eSPI device IO, upstream/downstream memory cycles.
  • Processor Direct eSPI Controller (to/from 1-4 eSPI devices, including EC)
    • EC/PCH eSPI device IO, upstream/downstream memory/completion cycles.
  • PCH Peripheral Channel Controller
    • PCH RTC IO cycles.
  • PCH eSPI controller
    • SPI/eSPI host/device/switch config, SPI/eSPI Config/MMIO and private registers.

Virtual Wire Channel:

  • PCH Direct eSPI controller
    • Processor PMC
    • Processor ITSS
    • Processor GPIO
    • PCH eSPI
  • Processor Direct eSPI Controller (to/from 1-4 eSPI devices, including EC)
  • PCH eSPI Virtual Wire Channel Controller
    • PCH GPIO/PMC/eSPI
  • PCH eSPI controller
    • DnX, host reset warn/ack, OOB reset warn ack, Device_​Boot_​ Load_​Done/Status; Error_​Fatal / Error_​NonFatal/NMI/Aggregated IRQ

OOB Channel:

  • PCH Direct eSPI controller
    • Processor PMC: OOB messages for EC (e.g. PECI).
    • Processor CSE: Primary OOB messages.
    • Processor Silicon Security Engine: Primary OOB messages.
  • Processor Direct eSPI Controller (to/from 1-4 eSPI devices, including EC)
  • PCH OOB Channel Controller
    • PCH CSE: Primary OOB messages.
    • PCH Silicon Security Engine: Primary OOB messages
    • PCH PMC: Primary OOB messages.
  • PCH eSPI controller
    • PCH temperature/RTC OOB messages.

Flash Channel:

  • PCH Direct eSPI controller
    • Processor BIOS: through PCH SPI controller, including both flash and RPMC
    • Processor CSE: through PCH SPI controller, including both flash and RPMC
    • Processor Silicon Security Engine: through PCH SPI controller
    • PCH SPI controller: Processor descriptor access/recovery
  • Processor Direct eSPI Controller (Device0/EC)
  • PCH Flash Channel Controller
    • PCH CSE: through PCH SPI controller, including both flash and RPMC
    • PCH Silicon Security Engine: through PCH SPI controller
    • PCH GbE: through PCH SPI controller
  • PCH SPI controller
    • PCH descriptor access/recovery