The M.2-ARINC429-4/8 (M.2 22mm x 60mm) board has an ARINC controller that supports ARINC 429 specifications. ARINC 429 (Aeronautical Radio Incorporated) is a specification that defines how avionics equipment and systems should communicate with each other. ARINC 429 employs a unidirectional data bus standard known as Mark 33 Digital Information Transfer System (DITS). Messages are transmitted and received at a bit rate of either 12.5kb/s or 100kb/s. The receiver input circuitry and logic are designed to directly meet the ARINC 429 specifications. The transmitter section provides the ARINC 429 communication protocol. The SPI data bus on the ARINC controller exchanges the 32-bit ARINC data word in two steps when either loading the transmitter or interrogating the receivers. The SRAM stores received data and transmitted data.