Advanced Communication Devices Corp.

Advanced Communication Devices Cororation

Jun Yu

Tak-Lap Tsui

Jay Jie Deng

Lian-Sheng Xie

Lian S Xie

The present invention includes an Ethernet frame switching system for receiving and transmitting data frames from and to a plurality of ports. The frame switching system includes a plurality of port control units for managing the transmission and reception procedural processes with a physical layer device. The frame switching system further includes a queue management unit (QMU) connected with data buses to the port control unit. The data frames received from or transmitted to the port control unit are managed by the QMU that these data frames received are transmitted directly to and data frame for transmission or retrieved directly from a single shared data frame buffer such that the local data frame buffer is not required in each of the port control units. Without these local data buffers, the QMU applies a novel link list queue management process to complete the writing and reading of data frame for transfer over the data bus in a single time-division multiplexed time slot such that no loss of data frame occurs. The data frame queue management further include a special technique for managing the broadcast frames by employing a broadcast frame counter together with the link list management scheme. The first-in-first-out order is maintained in combination with the unicast frames without requiring multiple data frame storage slots for the broadcasting frames such that high through put of frame switching is achieved without imposing additional memory requirements.

Simplified ethernet frame switching system architecture without local buffer requirement

A data frame switching apparatus has number data ports and a port traffic management unit for each port. Each port traffic management unit includes a physical layer unit for receiving and transmitting data frames, a serial shift register for temporarily storing a portion of each received data frame in serial data format, and a port controller for extracting each data frame's source and destination address from the portion of the data frame stored in the serial shift register. A crossbar switch connects any specified one of the data ports that is receiving a data frame to another one of the data ports so as to transmit the received data frame to a corresponding destination. A global traffic manager and lookup engine map the destination address of each received data frame to a corresponding destination port, determine the availability of the destination port, and when the destination port if available, send setup signals to the switch so as to connect the data port on which the data frame is being received to the destination port.

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Milpitas, CA, United States of America

Jun Yu