The COM20022I is a member of the family of Embedded ARCNET Controllers from Standard Microsystems Corporation. The device is a general purpose communications controller for networking microcontrollers and intelligent peripherals in industrial， automotive， and embedded control environments using an ARCNET protocol engine. The small 48 pin package， flexible microcontroller and media interfaces， eight-page message support， and extended temperature range of the COM20022I make it the only true network controller optimized for use in industrial， embedded， and automotive applications. Using an ARCNET protocol engine is the ideal solution for embedded control applications because it provides a deterministic token-passing protocol， a highly reliable and proven networking scheme， and a data rate of up to 10 Mbps when using the COM20022I. A token-passing protocol provides predictable response times because each network event occurs within a predetermined time interval， based upon the number of nodes on the network. The deterministic nature of ARCNET is essential in real time applications. The integration of the 2Kx8 RAM buffer on-chip， the Command Chaining feature， the 10 Mbps maximum data rate， and the internal diagnostics make the COM20022I the highest performance embedded communications device available. With only one COM20022I and one microcontroller， a complete communications node may be implemented.