Abstract: A method and apparatus are provided for implementing communications in a communications network. The apparatus for implementing communications includes a system interface to the communications network. A scheduler schedules enqueued cells and enqueued frames to be transmitted. A segmenter segments frames and cells in into cells or frames applied to a media adaptation block for transmission in a selected one of multiple modes.

Abstract: A method and Gigabit Ethernet communications adapter are provided for implementing communications in a communications network. A transmission queue is defined of data to be transmitted. A transmission rate is set for the transmission queue. Data to be transmitted are enqueued on the transmission queue. The transmission queue can be subdivided into multiple priority queues, for example, using time wheels, and a transmission rate is set for each transmission queue.

Abstract: A method and apparatus are provided for scheduling the transmission of cells and frames in a communications network. The transmission of cells and frames are scheduled utilizing a selected scheduling algorithm. The cell/frame scheduling algorithm includes the step of identifying a frame or cell transmission type. Responsive to the identified frame or cell transmission type, a frame multiplier value is identified. A target transmission time is calculated for the frame or cell transmission type utilizing the identified frame multiplier value. A method and apparatus optionally are provided for scheduling the transmission of packet pairs.

Abstract: A method and apparatus are provided for implementing cyclic redundancy check (CRC) calculation for data communications in a communications system. CRC calculation apparatus includes a CRC tree structure receiving a first CRC input, a data input of N−1 data input bytes; and a length input. The CRC tree structure includes a series of CRC trees. Each of the CRC trees has a seed CRC input, a fixed size data input and provides a CRC result output. The series of CRC trees are arranged in cascade with increasing data size inputs. A multiplexer control logic responsive to the length input selectively couples predefined data input bytes to predefined ones of the series of the CRC trees. The multiplexer control logic responsive to the length input couples the first CRC input to a selected one of the CRC trees; couples predefined CRC result outputs to predefined ones of the CRC trees; and utilizes a selected CRC tree to provide the overall CRC result.

Abstract: A rate based mechanism for determining which data to replace in a cache when the cache is full. The computer system processes data, which are associated with multiple channels or processes. These channels or processes have different, cyclic rates. When the cache is full, the system chooses the data to replace by selecting the data block in the cache that has the lowest rate and is the most recently used.

Abstract: A method and apparatus for implementing virtual memory having multiple selected page sizes are provided. A virtual address includes a map index and a frame offset. A selector mechanism receives the virtual address frame offset and generates an offset and index. A frame map table indexes the virtual address map index and the selector generated index and generates a base address. The frame map table generated base address and the selector generated offset are combined to provide a physical address.