1. laxmi

    Thread Starter Member

    Jun 19, 2009

    Please explain me the concept of SPI & I2C. What exactly these two protocol will do?. Impartance & which one is more efficient to use in microcontroller?

    Thanks in advance.
  2. bertus


    Apr 5, 2008
  3. Papabravo


    Feb 24, 2006
    Each of them is intended for the purpose of moving serial data from one chip to another over a relatively short distance. A short distance is one that does not require transceivers or cables more than a few inches in length. Primarily this means the chips are on the same board, but board to board connections are possible.

    SPI is capable of full duplex operation at higher speed and usually requires 4 wires. I2C requires only two wires, runs at lower speed and has a slightly more involved half duplex protocol.
  4. BMorse

    AAC Fanatic!

    Sep 26, 2009
    Both can be usefull in their own way and interface easily to just about any uc.... but, if you have more than one device for the uc to communicate with, I2c would be the way to go since multiple devices can share the same 2 wires, SPI can share its data and clock lines too, but usually you would need some extra I/O's to control each devices chip select.... So in essence both are relatively the same in function, one is just faster but uses more I/O's than the other.