Inter-Integrated Circuit
- It is a synchronous mode of communication.
- As it synchronous so the the communication between two devices id based on a common signal called serial clock pulse, and master have the control of this serial clock pulse.
- It uses 2 wire bus
- SCL : Serial Clock ( controls communication )
- SDA : Serial Data Access ( serial data transmission bus)
- It follows many master many slaves.
- It is address oriented communication, as every slave has a unique address.
- Max no of slaves are limited to 2^7 (2 raise to power 7).
- It is half duple mode of communication.
- While transmitting data, MSB is sent first.
- Master can be transmitter and receiver as well.
- Master generates serial clock pulse and initiate communication, other device will act as slave as start responding as per their address, as this is address oriented mode of communication.
- Master does't have any address, so not possible for slave to send commands to master until master request slave to do so.
Working principle
- Master will start communication with sending a start bit.
- With every clock pulse from high to low, a bit of data is transmitted by serial data bus.
- Data is exchanged only and only when SCL ( serial clock pulse ) is low.
- Master will transmit slave address to whom it wants to communicate.
- After address master will send memory address to slave that master wants to access.
- After memory address, master will read/write data at that location.
- Master will stop communication with sending a stop bit.
we will discuss all stages one by one. Go back and read further.