SPI & I2C Comparision

 The SPI was developed by Motorola in the mid-1980s The I2C was invented in 1982 by Philips Semiconductor (now NXP Semiconductors).
Communicate in full-duplex mode using a master-slave architecture with a single master. Communicate in half-duplex mode using multi-master/slave architecture.
SPI (Serial Peripheral Interface) is a 4-wire, the clock signal is generated by the master, and there are two data lines – MOSI (Master Out Slave In) and MISO (Master In Slave Out). I2C (Inter-Integrated-Circuit) is a 2-wire, One wire carries a clock signal generated by the master, and the other wire carries data, generated by either the master or the slave.
Not address specific protocol. SPI devices do not have an address, so although many of them can share the bus, each requires its own chip select line.  Number of pins = 3 + n, where n = number of slaves. So that it is good for short distance Address oriented protocol.  All peripheral devices have an address, so many devices can work together on the same two-wire bus. Number of pins = 2. It is good for long-distance.
Acknowledgment bit is not supported, so the controller could not verify the sent data. Controller gets the acknowledgment bit (ACK/NACK) after each byte. So that the controller ensures the data sent is received by the slave device.

Not limited to any maximum clock speed


  • 10 kbit/slow-speed mode
  • 100 kbit/s standard mode
  • 400 kbit/s Fast mode

  • High-speed DAC & ADC
  • Sensors – touch screen, video game controller
  • Camera lenses
  • RTC(real-time clock)
  • LCD driver
  • Memory interfaces

  • Low-speed DAC
  • LCD driver
  • Accessing memory



2 thoughts on “SPI & I2C Comparision

  • February 8, 2021 at 1:46 pm

    Remarkable! Its truly amazing article, I have got much clear idea concerning from this post. Bill Cordy Delanty

  • February 13, 2021 at 12:20 pm

    Thank you so much, Joyce. That means so much to me! <3 Audi Benton Ackley


Leave a Reply

Your email address will not be published. Required fields are marked *