3Com Corporation

U.S. Ethernet Innovations, LLC

Cynthia Zikmund

Glenn William Connery

Richard S Reid

Richard J Hausman

Paul William Sherer

Niles E Strohl

James P Rivers

In a Local Area Network (LAN) system, an Ethernet adapter exchanges data with a host through programmed I/O (PIO) and FIFO buffers. The receive PIO employs a DMA ring buffer backup so incoming packets can be copied directly into host memory when the PIO FIFO buffer is full. The adapter may be programmed to generate early receive interrupts when only a portion of a packet has been received from the network, so as to decrease latency. The adapter may also be programmed to generate a second early interrupt so that the copying of a large packet to the host may overlap reception of the packet end. The adapter to begin packet transmission before the packet is completely transferred from the host to the adapter, which further reduces latency. The minimal latency of the adapter allows it to employ receive and transmit FIFO buffers which are small enough to be contained within RAM internal to an Application Specific Integrated Circuit (ASIC) containing the transceiver, ethernet controller, FIFO control circuitry and the host interface as well.

Programmed I/O ethernet adapter with early interrupts for accelerating data transfer

In a Local Area Network (LAN) system, an ethernet adapter exchanges data with a host through programmed I/O (PIO) and FIFO buffers. The receive PIO employs a DMA ring buffer backup so incoming packets can be copied directly into host memory when the PIO FIFO buffer is full. The adapter may be programmed to generate early receive interrupts when only a portion of a packet has been received from the network, so as to decrease latency. The adapter may also be programmed to generate a second early interrupt so that the copying of a large packet to the host may overlap reception of the packet end. The adapter to begin packet transmission before the packet is completely transferred from the host to the adapter, which further reduces latency. The minimal latency of the adapter allows it to employ receive and transmit FIFO buffers which are small enough to be contained within RAM internal to an Application Specific Integrated Circuit (ASIC) containing the transceiver, ethernet controller, FIFO control circuitry and the host interface as well.

Programmed I/O ethernet adapter with early interrupt and DMA control for

In a Local Area Network (LAN) system, an ethernet adapter exchanges data with a host through programmed I/O (PIO) and FIFO buffers. The receive PIO employs a DMA ring buffer backup so incoming packets can be copied directly into host memory when the PIO FIFO buffer is full. The adapter may be programmed to generate early receive interrupts when only a portion of a packet has been received from the network, so as to decrease latency. The adapter may also be programmed to generate a second early interrupt so that the copying of a large packet to the host may overlap reception of the packet end. The adapter may also be programmed to begin packet transmission before the packet is completely transferred from the host to the adapter, which further reduces latency. The minimal latency of the adapter allows it to employ receive and transmit FIFO buffers which are small enough to be contained within RAM internal to an Application Specific Integrated Circuit (ASIC) containing the transceiver, ethernet controller, FIFO control circuitry and the host interface as well.

Programmed I/O ethernet adapter with early interrupts for accelerating

Apparatus for simulating a stack structure using a single register and a

Growing community of inventors

Boulder Creek, CA, United States of America

Cynthia Zikmund