Abstract: A network processor or other type of processor includes an interface comprising a plurality of signal lines, and interface circuitry adapted to receive clock signals for respective interface clock domains of the processor. The interface circuitry comprises a plurality of sampling registers clocked by respective ones of the clock signals. The interface circuitry is configurable in a variety of different configurations, each providing a different association between designated subsets of the signal lines and the clock domains of the processor.

Abstract: An apparatus for detecting sticky and a leading one includes first circuitry capable of detecting both sticky and a leading one. The apparatus further includes second circuitry that determines whether a sticky or a leading one detect is required. Depending upon that determination, the second circuitry controls the first circuitry to perform a sticky detection or a leading one detection. A method practiced by the apparatus includes the steps of detecting either sticky or a leading one utilizing the same circuitry, determining whether a sticky or a leading one detect is required, and controlling the circuitry in accordance with the determination of whether a sticky or a leading one detect is required.

Abstract: A technique for use in an I/O channel to increase bus bandwidth during DMA data transfers between main system memory and a communication link is disclosed, including a pair of buffers, a plurality of counters adapted to selectively contain a count of data increments therein, and enhanced DMA control logic for monitoring buffer data content amount, and at a predetermined time during a given transfer initiating a bus arbitration so that it is completed simultaneously with the given transfer, thereby enabling the next data transfer from the buffer in use to immediately commence.

Abstract: An interface circuit for providing an interface with the parallel data bus that transfers information in a multiple of formats. The interface includes a control circuit that receives or sends control signals from or to the parallel bus to regulate the data transfer and to specify one of the plurality of formats. An addressing circuit, connected to the control circuit, is provided for computing addresses for each of the data received or sent according to the specified format. An accessing circuit connected to the bus, control and address circuits is provided to store or retrieve data from or to the bus according to the computed data addresses. This interface provides a means to serialize data when, in one format, the first word of a data transfer is provided on one part of the data bus but, in a second format, the first data word is provided on another part of the data bus.

Abstract: A timer including a counter circuit that continuously provides an output of an iteratively increasing sequence of bits. The timer includes a timeout data circuit that forms a timeout data word from a specified time period and a first counter circuit output. A register is provided that stores the timeout data word at an address formed from a second counter circuit output. A comparison circuit is provided that compares each counter output with a timeout data word at the address formed from that counter output and provides a timeout signal when they are equal. This timer includes a constantly incrementing counter to address a register that includes a multiple of timeout condition specifications, and as a determination of when the timeout conditions stored in the register occur.