The AT75C221, Atmel's latest device in the family of smart internet appliance processors (SIAPTM), is a high-performance processor designed for professional internet appliance applications such as the Ethernet IP phone. The AT75C221 is built around an ARM7TDMI microcontroller core running at 40 MHz with an OakDSPCore coprocessor running at 60 MHz and a dual Ethernet 10/100 Mbits/sec MAC interface. In a typical standalone IP phone, the DSP handles the voice processing functions (voice compression, acoustic echo cancellation, etc.) while the dual-port Ethernet 10/100 Mbits/sec MAC interface establishes the connection to the Ethernet physical layer (PHY) that links the network and the PC. In such an application, the power of the ARM7TDMI allows it to run a VoIP protocol stack as well as all the system control tasks.