A Scalable Load Balanced Birkhoff-von Neumann Symmetric TDM Switch IC for High-Speed Networking Applications

Abstract

For the first time, a scalable load balanced Birkhoff-von Neumann TDM switch IC with SERDES interface circuits for high speed networking applications was implemented. Any NtimesN Birkhoff-von Neumann TDM switch could be constructed recursively from the designed TDM switch IC to achieve switching capacity of hundred gigabits per second or higher. The TDM switch IC contained a digital 8times8 TDM switch core with 8B10B codecs and analog SERDES I/O interfaces. In the I/O interfaces, eight 2.56/3.2Gbps dual-mode 16/20:1 SERDES with CML buffers were developed. The 16/20:1 instead of 8/10:1 serializer and deserializer were used to reduce the required operating frequency in the switch core by half. New half-rate architectures and all static CMOS gates were used in the 16/20:1 serializer and deserializer for the low power consumption. A wide-band CML I/O buffer with our patented PMOS active load scheme was developed. All the implementations were based on the 0.18 mum CMOS technology. Test results showed a 20 Gbps switching capacity for the 8times8 TDM switch IC.