Skip to content

SPI

Serial Peripheral Interface — modes, polarity, and timing across vendor flavors.

Foundation 1h 20m readLow-speed

Four-wire full-duplex protocol, much faster than I²C. Ubiquitous for flash memory, ADCs, displays.

What you'll learn

  • CPOL/CPHA modes (the source of half of all SPI bugs)
  • Master and slave state machines
  • Multi-slave: chip-select vs daisy chain
  • Quad and dual SPI for high-bandwidth flash
  • Building a multi-slave SPI master