The MIPI RF Front End (RFFE) specification was developed to form a standard bus protocol for devices in a radio frequency signal path to minimize noise coupled into the devices from digital signals and to solve high configuration speed requirements for MIMO applications. RFFE busses allow only a single master that drives a clock (SCLK) and data (SDATA) to multiple slave devices; the very low pin count (two pins) benefits overall system simplicity. This example includes an RFFE Master suitable for controlling an RFFE bus and an RFFE Slave. Note that the RFFE standard uses signaling levels (1.2 Volt or 1.8 Volt) that are not directly compatible with the NI PXIe-5644R DIO (3.3 V TTL). Therefore, external signal conditioning circuitry is required for any RFFE bus that is interfaced to the NI PXIe-5644R.