I2C Communication

I2C Communication

1. Features

- 2 Signals

1) SDA (Serial Data): Signal to transmit

2) SCL (Serial Clock): Signal to synchronize Master and Slave

- Control devices by combination of SDA and SCL

- SDA's Default: 1(Pull-up)

* Once communication gets started, SDA should be changed while SCL is zero.

Because, Master and Slave are synchronized.

- SCL Packet: 9 bit (7 bit: Address + 2 bit: R/W)

- Data Packet: 9 bit (8 bit: Data + 1 bit: ACK)

* ACK is to check if data is received well.

2. General Flow

Communication starts -> Address Packet -> Data Packet -> Stop communication

3. Advantages

1) Be able to control devices with only 2 signal wires

-> Devices have to have different address (Transmitted by 'packet')

2) 1:N Communication

-> One Master chip can manage several Slave chips paralleled.

3) Synchronized communication

-> I2C Communication is not much dependent on the time unlike RS232C.

-> Even if timing is not exactly matched, data signal could be adjusted along the clock signal.

* 관련 레지스터 공부가 필요!