The Digital Buses and Protocols library is a part of the the LabVIEW FPGA IPNet and provides FGPA IP and examples related to communicating via digital buses and protocols like SPI, I2C and Serial. These examples are installed to the LabVIEW\examples\FPGA\ folder for the version of LabVIEW you install support for.

SPI (Serial Peipheral Interface): SPI is a commonly used communication protocol for both integrated circuit communication and embedded sensors. The protocol operates in full duplex with a single master and multiple slaves per port. This allows the flexibility of communicating with several different devices through a single port where each device can have its own clock rate and command set.

I2C: I2C is a synchronous protocol based on a two wire bus. The I2C bus is a multi-master bus with the ability to have multiple slave devices that can all be independently controlled. All communication between a master and slave device fit into three basic sequence formats: Master-to-Slave Write, Master-Slave Read, or a combined Master-to-Slave Write with Read sequence.

Serial (RS-232/RS-422/RS-485): Serial is a device communication protocol that sends and receives bytes of information one bit at a time. It is standard on most PCs and is a common communication method with various electrical instruments. Typically, engineers use serial to transmit ASCII data. Because serial is asynchronous, the port can transmit data on one line while receiving data on another.

Additional Information:
The libraries provided here are part of the LabVIEW FPGA IPNet. IPNet is a one-stop resource for browsing, understanding, and downloading LabVIEW FPGA functions or IP (intellectual property) and is a collection of FPGA IP and examples gathered from the LabVIEW FPGA function palette, internal National Instruments developers, and the LabVIEW FPGA community. For more information, see the links in the Resources tab on the product page.