i2c
pin definition
There are two lines(SDA, SCL) in i2c protocol, the SDA is used to send/receive data, it's biredirectional, and SCL is the clock.
The priciple of data transfer in i2c protocol:
- IDLE: Both SCL and SDA are keep in high state.
- SCL in high state, the data in SDA is valid and its value cannot be changed. The exceptions are:
- START: SDA from '1' to '0'
- STOP: SDA from '0' to '1'
- SCL in low state, the state of SDA is updatable.