Editing Serial Peripheral Interface (section)

==Applications==
{{Multiple image
| image1            = ATI Radeon X1300 256MB - Atmel 25F512AN-5397.jpg
| caption1          = SPI Memory by [[Atmel]]
| image2            = ADSV-931 Mini Docking Station - LAN module - Fairchild 93C46-93553.jpg
| caption2          = [[Fairchild Semiconductor|Fairchild]] EEPROM using [[#Microwire|Microwire]]
| image3            = Sumup AIR1 E205 - board - Microchip 26F032B-1521.jpg
| caption3          = [[Microchip Technology|Microchip]] 32-Mbit [[#QPI/SQI|SQI]] Flash Memory
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SPI is used to talk to a variety of peripherals, such as
* Sensors: [[temperature]], [[pressure]], [[analog-to-digital converter|ADC]], [[touchscreens]], [[video game controllers]]
* Control devices: [[audio codec]]s, [[digital potentiometer]]s, [[digital-to-analog converter|DACs]]
* Camera lenses: [[Canon EF lens mount]]
* Memory: [[flash memory#Serial flash|flash]] and [[EEPROM#Serial bus devices|EEPROMs]]
** Any [[MultiMediaCard|MMC]] or [[Secure Digital|SD]] card (including [[Secure Digital#SDIO|SDIO]] variant{{NoteTag|Not to be confused with the SDIO (Serial Data I/O) line of the half-duplex implementation of SPI sometimes also called "3-wire" SPI. Here e.g. MOSI (via a resistor) and MISO (no resistor) of a master is connected to the SDIO line of a slave.|name=3wireSDI}})
* [[Real-time clock|Real-time clocks]]
* [[LCD|LCDs]], sometimes even for managing image data
* [[Shift registers]] for additional I/O<ref name=":3" /><ref name=":2" />

[[Printed circuit board|Board]] real estate and wiring savings compared to a [[Parallel communication|parallel]] bus are significant, and have earned SPI a solid role in embedded systems. That is true for most [[system-on-a-chip]] processors, both with higher-end 32-bit processors such as those using [[ARM architecture|ARM]], [[MIPS architecture|MIPS]], or [[PowerPC]] and with lower-end microcontrollers such as the [[Atmel AVR|AVR]], [[PIC microcontroller|PIC]], and [[MSP430]]. These chips usually include SPI controllers capable of running in either master or slave mode. [[In-system programming|In-system programmable]] AVR controllers (including blank ones) can be programmed using SPI.<ref>{{cite web |url=http://www.atmel.com/dyn/resources/prod_documents/DOC0943.PDF |title=AVR910 - In-system programming |archive-url=https://web.archive.org/web/20110302123348/http://www.atmel.com/dyn/resources/prod_documents/DOC0943.PDF |archive-date=2011-03-02}}</ref>

Chip or [[FPGA]] based designs sometimes use SPI to communicate between internal components; on-chip real estate can be as costly as its on-board cousin. And for high-performance systems, [[FPGA]]s sometimes use SPI to interface as a slave to a host, as a master to sensors, or for flash memory used to bootstrap if they are SRAM-based.

The full-duplex capability makes SPI very simple and efficient for single master/single slave applications. Some devices use the full-duplex mode to implement an efficient, swift data stream for applications such as [[digital audio]], [[digital signal processing]], or [[channel (communications)|telecommunications channels]], but most off-the-shelf chips stick to half-duplex request/response protocols.