The Broadcom SPI Controller Driver is a Windows driver that allows the Broadcom Serial Peripheral Interface (SPI) controller hardware to communicate with a computer's operating system. SPI is a communication protocol used for data transfer between microcontrollers and peripheral devices like sensors, memory chips, or other integrated circuits (ICs). Broadcom SPI controllers are often used in embedded systems, development boards, or devices that need to communicate with SPI-based peripherals.

The SPI controller driver ensures that Windows can correctly interact with Broadcom hardware that uses the SPI protocol for communication.