The SC18IS602B is designed to serve as an interface between a standard I2C-bus of a microcontroller and an SPI bus. This allows the microcontroller to communicate directly with SPI devices through its I2C-bus. The SC18IS602B operates as an I2C-bus target-transmitter or target-receiver and an SPI . The SC18IS602B controls all the SPI bus-specific sequences, protocol, and timing. The SC18IS602B has its own internal oscillator, and it supports four SPI chip select outputs that may be configured as GPIO when not used.