1.. _espi_api: 2 3Enhanced Serial Peripheral Interface (eSPI) Bus 4############################################### 5 6Overview 7******** 8 9The eSPI (enhanced serial peripheral interface) is a serial bus that is 10based on SPI. It also features a four-wire interface (receive, transmit, clock 11and target select) and three configurations: single IO, dual IO and quad IO. 12 13The technical advancements include lower voltage signal levels (1.8V vs. 3.3V), 14lower pin count, and the frequency is twice as fast (66MHz vs. 33MHz) 15Because of its enhancements, the eSPI is used to replace the LPC 16(lower pin count) interface, SPI, SMBus and sideband signals. 17 18See `eSPI interface specification`_ for additional details. 19 20 21API Reference 22************* 23 24.. doxygengroup:: espi_interface 25 26.. _eSPI interface specification: 27 https://downloadmirror.intel.com/27055/327432%20espi_base_specification%20R1-5.pdf 28