SPI Interface

SPI interface, full name is Serial Peripheral Interface, is a common interface type mainly used for communication between microcontrollers and other devices. This interface utilizes the concept of master device and slave device, where data transmission starts from the master device and flows to the slave device.

There are mainly four lines in an SPI interface: clock line (SCLK), master input slave output (MISO), master output slave input (MOSI), and chip select line (SS). The clock line driven by the master device is used for synchronous data transfer. MISO and MOSI lines serve for two-way data exchange. The chip select line is used to distinguish which slave device the master device wants to communicate with.

The advantage of SPI interface is its high transfer speed, but it also requires more hardware resources. Therefore, SPI interfaces are often used in situations that require fast data transfer and are not strictly limited in hardware resources, such as SD cards, LCD display drivers, etc.

That's a basic introduction to the SPI interface, which establishes an efficient, fast channel for information exchange between microcontrollers and peripherals.