Intel® Pentium® Silver and Intel® Celeron® Processors Datasheet, Volume 1
Enhanced Serial Peripheral Interface (eSPI)
The PCH provides the Enhanced Serial Peripheral Interface (eSPI) to support connection of an EC to the platform.
eSPI operates at 1.8 V only. This interface is not shared and distinct from the SPI interface used for flash device and TPM. The eSPI interface supports 20 MHz, 24 MHz, 30 MHz, 48 MHz, and 60 MHz and up to Quad Mode with one chip select.