Similarities and differences between SPI and IIC

1. The same thing

1. Serial communication is adopted 、 How to synchronize
2. All adopt TTL level , The transmission distance is similar to the application scenario
3. Both work in master-slave mode

2. Difference

1. IIC It's half duplex ,SPI Full duplex
2. IIC by 2 Line system ,SPI by 4 Line system
3. IIC Speed is 100Kbps- -3.4Mbps,SPI What is the speed MHz - - Dozens of MHz
4. IlC There is a response mechanism ,SPI No response mechanism
5. IIC Address by broadcasting the slave address to the bus ,SPI Address by sending a chip selection signal to the corresponding slave
6. IIC The clock polarity and clock phase are fixed ,SPI The clock polarity and clock phase can be set by yourself