Serial Peripheral Interface

A 4-wire Serial Communication protocol developed by Motorola. Similar to I2C and UART.

• Full Duplex Often used to transfer data between a smart controller and less smart peripheral device (sensors, clocks, controllers).

Topology

A master node is connected to one or more slaves with 4 wires between them.

• Chip Select(CS) : Chooses communication target. Active Low
• Synchronous Clock(SCLK) : Provides timing
• Master Out Slave In(MOSI) : Data transmitted by master
• Master In Slave Out(MISO): Data recieved by master. Not required in one-way communication (i.e Displays)

Concepts

• Serial Peripheral Interface Protocol
• Clock Polarity
• Clock Phase
• SPI Modes
• SPI Multislave Configurations