Serial Peripheral Interface

The master (controller) device originates the frame for reading and writing. The SPI may be accurately described as a synchronous serial interface. But it is different from the Synchronous Serial Interface (SSI) protocol.

 Developer 
The interface was developed by Motorola in the mid-1980s. Later it  has become a de facto standard.
 Pros and cons 

 Advantages 

 Full duplex communication in the default version of this protocol
 Push-pull drivers (as opposed to open drain) provide good signal integrity and high speed
 Higher throughput than I²C or SMBus. Not limited to any maximum clock speed, enabling potentially high speed
 Complete protocol flexibility for the bits transferred
 Not limited to 8-bit words
 Arbitrary choice of message size, content, and purpose
 Simple software implementation

 Disadvantages 

 Requires more pins on IC packages than I²C, even in the three-wire variant
 No in-band addressing; out-of-band chip select signals are required on shared buses
 SPI does not support hot swapping (dynamically adding nodes)
 Some variants like dual SPI, quad SPI, and three-wire serial buses defined below are half-duplex.

 Applications 

link=//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/ATI_Radeon_X1300_256MB_-_Atmel_25F512AN-5397.jpg/220px-ATI_Radeon_X1300_256MB_-_Atmel_25F512AN-5397.jpg|thumb|SPI Serial Memory by Atmel |188x188px

 Memory: SD Card , MMC , EEPROM , Flash.
 Sensors: Temperature and Pressure.
 Control Devices: ADC , DAC , digital POTS and Audio Codec.
 Others: Camera Lens Mount, touchscreen, LCD, RTC, video game controller, etc.

 Sources 

 Other websites 

 Intel eSPI (Enhanced Serial Peripheral Interface)
 SPI Tutorial
Category:Computer buses