Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » S »

SPI

(1) Short for Serial Peripheral Interface, a full-duplex synchronous serial interface for connecting low-/medium-bandwidth external devices using four wires. SPI devices communicate using a master/slave relationship over two data lines and two control lines:

  • Master Out Slave In (MOSI): supplies the output data from the master to the inputs of the slaves.
  • Master In Slave Out (MISO): supplies the output data from a slave to the input of the master. It is important to note that there can be no more than one slave that is transmitting data during any particular transfer.
  • Serial Clock (SCLK): a control line driven by the master, regulating the flow of data bits.
  • Slave Select (SS): a control line that allows slaves to be turned on and off with hardware control.

(2) Short for System Packet Interface, a point-to-point interface standard, allows network equipment designers to develop an array of next-generation multi-service switches and routers to support multi-service traffic with aggregate bandwidths up to OC-192 (10 Gb/s) and beyond, enabling them to dramatically increase system performance. It is a family of Interoperability Agreements from the Optical Internetworking Forum (OIF) which include:

  • System Packet Interface Level 5 (SPI-5): OC-768 System Interface for Physical and Link Layer Devices. (OIF documentation)
  • System Packet Interface Level 4 (SPI-4) Phase 2: OC-192 System Interface for Physical and Link Layer Devices.(OIF documentation)
  • System Physical Interface Level 4 (SPI-4) Phase 1: A System Interface for Interconnection Between Physical and Link Layer, or Peer-to-Peer Entities Operating at an OC-192 Rate (10 Gb/s)  (OIF documentation)
  • System Packet Interface Level 3: OC-48 System Interface for Physical and Link Layer Devices (OIF documentation)






TECH RESOURCES FROM OUR PARTNERS
LATEST ARTICLES
8 Agenda Apps to Help Students Stay Organized

Webopedia's student apps roundup will help you to better organize your class schedule and stay on top of assignments and homework. Read More »

20 Ways to Shorten a URL

If you need to shorten a long URL try this list of 20 free online redirection services. Read More »

Top 10 Tech Terms of 2015

The most popular Webopedia definitions of 2015. Read More »

STUDY GUIDES
Computer Architecture Study Guide

This Webopedia  study guide describes the different parts of a computer system and their relations. Read More »

Network Fundamentals Study Guide

Networking fundamentals teaches the building blocks of modern network design. Learn different types of networks, concepts, architecture and... Read More »

The Five Generations of Computers

Learn about each of the five generations of computers and major technology developments that have led to the current devices that we use today. Read More »