The document mainly introduces the features and characteristics of the 33780 chip, including independent DBUS I / Os, common SPI interface, open-drain interrupt output, maskable interrupt for send and receive data status, automatic message cyclic redundancy check (CRC) generation and checking, four-stage transmit and receive buffers, 8- to 16-bit messages with 0- to 8-bit CRC, independent frequency spreading for each channel, etc.