A SPI Host adapter is a kind of electronic equipment that formally allows connecting a 'host' to a SPI (Serial Peripheral Interface) interconnection. Usually, this term refers to an instrument that allows communicating with a set of SPI peripherals from a PC (the 'host'). Currently, Byte Paradigm proposes 'USB SPI Host Adapters', which means that the instrument uses a USB port as a connection with the PC.

SPI is a 'master-slave' type of protocol (please click here for an introduction to SPI and I²C serial protocols ).
A SPI Host Adapter can sometimes be called a 'SPI Master', since it is used as such on SPI interconnect. Basically, a SPI Host Adapter allows sending SPI commands as a master onto a SPI bus. These commands can be 'writing' data to one or multiple slaves and 'reading' data from them.

SPI protocol defines many parameters such as the clock edge used to sample data, the clock IDLE level (these 2 parameters are defined with the 'SPI mode'), the polarity of the signals, the length of each transfer. SPI protocol does not define 'high-level' protocols such as the addressing space of each slave or the commands for writing/reading data. There are also many protocols used today that slightly derive from the formal SPI protocol (for instance, a '3 wires procotol', which uses 3 signal lines instead of 4, with a bi-directional data line).

A SPI Host Adapter should provide controls and options to cover a maximum of variations of the SPI protocol.

Need help to choose your SPI Adapter? Click here to access our SPI Adapter Selection Guide.

SPI Storm : 100 MHz USB SPI Adapter with dual-SPI, quad-SPI & custom serial protocol support and 8-bit digital pattern generator SPI Storm is our latest generation serial protocol host adapter designed to work with our new SPI Storm Studio software (click here to download and for free trial)
SPI Xpress : 50 MHz SPI Master & Analyzer SPI Xpress is designed to work with 8PI Control Panel software
GP Series devices in SPI mode of operation : 50 MHz SPI Master & Analyzer GP Series devices are designed to work with 8PI Control Panel software

 Remarks: GP Series are multi-function devices which can be used in other modes as well. 'SPI' is the mode of operation for SPI Host Adapter (SPI Master) and SPI Analyzer. The interface software and available functionalities of SPI Xpress and GP Series devices in SPI mode of operation are identical.

Read more:
	White paper: 'Solutions for SPI protocol testing and debugging in embedded system'
	White paper: 'Introducing SPI Storm'