Digital Equipment Corporation

Gideon Paul

Philippe Klein

Simoni Ben-Michael

Aviad Wertheimer

Aviad Werthimer

A method to reduce the rate of interrupts by the central processing unit (CPU) without any loss of interrupts. The method uses two parameters. The first parameter sets the event threshold, which is the maximum value of consecutive events allowed to occur, for example, the maximum number of received data packets before an interrupt is posted (for example, a receive interrupt) to the CPU. The second parameter sets the event time-out, which is the maximum time an event can be pending before posting an interrupt to the CPU. The second parameter is needed since the flow of events in the system is unpredictable and without the time-out limit handling of the event can be delayed indefinitely.

Method for reducing the rate of interrupts in a high speed I/O controller

A method implemented by a computer network adapter for automatic retransmission of any packet involved in an unsuccessful transmission attempt due to transmit buffer underflow conditions entails the steps of (a) stopping the transmission; and (b) retrying another transmission of the packet for up to a predetermined number of attempts with an increased transmit threshold. The transmit threshold is the number of bytes of data of the packet involved in the transmission that are stored in the transmit buffer prior to start of transmission. Preferably, for the initial transmission attempt, the adapter requires only a small number of bytes of the packet to be stored in the transmit buffer. After occurrence of a buffer underflow condition, the adapter attempts a retry in accordance with the algorithm only after a substantially larger portion of the packet has entered the transmit buffer for transmission. If any retry succeeds, the adapter need not issue an interrupt.

Growing community of inventors

Jerusalem, Israel

Gideon Paul