Add robust and reliable isolation to high-speed SPI communication

摘要

Serial Peripheral Interface (SPI) is an inter-device bus protocol that provides fast, synchronous, and full-duplex communication between a master and one of several slave devices. The master device - such as an MCU or FPGA - drives the clock and selects a slave device, such as an ADC or digital output driver, to address. Every SPI device consists of a single shift register and control circuitry so that the selected device can simultaneously transmit and receive signals. There are four signals used in SPI communication, as shown in Fig. 1: 1. SCLK: The synchronous clock used by all devices. The master drives this clock and the slaves receive it. Note that SCLK can be gated and doesn't need to be driven between SPI transactions. 2. MOSI: Master Out, Slave In. Also called DO on the master or DI on the slave. This is the main data line driven by the master to all slaves on the SPI bus. Only the selected slave clocks data from MOSI.