IIC and SPI

In the digital communication protocol suite, IIC and SPI are often referred to as "small" protocols,

Compared to Ethernet, USB, SATA, PCI-Express, etc., the transmission speed reaches hundreds of gigabytes per second.

The "big" protocol is for communication between systems outside the system,

The "small" protocol is used for communication between chips in the system, and there is no indication that the "big" protocol is necessary to replace the "small" protocol.

The existence and popularity of IIC and SPI reflect the philosophy of "enough is enough".

IIC: 100Kbps/400K/3.84M | Multi-Master Transfer Bytes | SDA+ SCK

• First, each IIC device has a unique seven-digit device address;
• Second, the data frame size is 8-bit bytes;
• Third, certain data bits in the data (frame) are used to control the start, stop, direction (read and write) and acknowledgement mechanism of the communication.

SPI: | >10M | Single master multi-slave transmission data stream | Simple structure and easy to expand |

[Master and Slave] must use the same operating parameters - SCLK, CPOL and CPHA to function properly;