Abstract: Initialization of a bidirectional, self-timed parallel interface with capacitive coupling is provided. The self-timed interface includes master and slave nodes connected by a parallel bus comprising multiple AC differential wire pairs. The initialization includes automatically testing at least one wire pair of the multiple AC differential wire pairs for conductivity failure, wherein the testing is responsive to a link reset signal of a first frequency. The automatically testing includes employing a link test signal of a second frequency to test the at least one wire pair of the multiple AC differential wire pairs. The second frequency is a lower frequency than a third, operational signal frequency of the self-timed parallel interface, and the first frequency and the second frequency comprise different frequencies. An initialization testing and handshake approach between the master node and slave node is also provided.

Abstract: A method is disclosed for instructing a computing system to allocate a trace array from an original cache memory, where the method includes dividing the original cache memory into a reduced-size cache memory and a trace array, permitting storage of trace signal data into the trace array, and permitting retrieval of the trace signal data from the trace array.

Abstract: A method is disclosed for instructing a computing system to allocate a trace array from an original cache memory, where the method includes dividing the original cache memory into a reduced-size cache memory and a trace array, permitting storage of trace signal data into the trace array, and permitting retrieval of the trace signal data from the trace array.

Abstract: A transmission line for carrying digital signals is provided with auxiliary line drivers at the receiver end, which are used in combination with the data line driver at the transmitting end to apply a sequence of sets of test voltages onto the line. The voltage resulting at the receiver input is used to detect open signal conductors and/or shorts in the receiver.

Abstract: A system and method for asynchronously receiving data blocks, in parallel, across multiple fibers in a serial manner. Frame groups are provided as a mechanism to transmit associated data serially on each fiber and tie the data being transmitted together. The frame groups do not have sequence numbers, therefore, the receiver determines which frames are part of a frame group by the arrival times of the individual frames. The transceivers for each member of the parallel bus examine the received bit stream to extract frames and continuous sequences. For each member of the parallel bus there are independent receive buffers, and these buffers are controlled by independent states. The states inhibit erroneously generated frames from corrupting the contents of the receive buffers and inhibit the loading of the buffers after errors on the link. These states also control the loading of the receive buffers after retransmission of a buffer area.

Abstract: A system and method for asynchronously transmitting data blocks, in parallel, across multiple fibers in a serial manner. Frame groups are provided as a mechanism to transmit associated data serially on each fiber and tie the data being transmitted together. The frame groups can be prematurely ended on any 256 byte block boundary for several purposes, and all the frames of a given group must contain the same number of information field data words. Allowing frame groups to be ended on arbitrary block boundaries allows their transmission to start before all of the information field for the frame group has been received from a shared main processor storage. This capability of ending frame groups also allows high priority frame groups to interrupt the transmission of a relatively long data frame. Finally, the capability to end the frame group protects the information field of a stalled frame group since the CRC is sent and the idle sequence is resumed.

Abstract: A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect header bits in the frame that identify the buffer set and the frame type. In this case, the entire frame is lost and the operation usually results in a timeout of the operation. By using this state information some of these lost frames can be recovered avoiding the lengthier timeout recovery procedure.

Abstract: A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each outstanding request for each buffer set is individually timed to detect lost frames, and each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect only the information field and there is enough information in the header to identify the frame. A request can then be sent back to the other end of the fibers to retransmit the frame. In some instances, the frame cannot be retransmitted because the content of the data may have been changed by other operations in the systems. To speed recovery in these situations, the requester of the retransmitted frame sets a much shorter timer while waiting for the response since the retransmitted frame will be sent quickly, if at all.

Abstract: A system and method for asynchronously transmitting data blocks, in parallel, across multiple fibers in a serial manner. Frame groups are provided as a mechanism to transmit associated data serially on each fiber and tie the data being transmitted together. The frame groups do not have sequence numbers, therefore, the receiver determines which frames are part of a frame group by the arrival times of the individual frames. The transceivers for each member of the parallel bus asynchronously achieve synchronism from either end of the fiber. A receiver of a transceiver determines a relative skew on a conductor of a link by performing skew measurements on a series of calibration frames sent by a transmitter on another end of said link. A skew monitor performs skew measurements and includes a plurality of skew measurement registers for measuring the relative skew between frames of a frame group, each register having an input from a skew counter, and outputs coupled to a microprocessor controlling the monitor.

Abstract: A system and method for asynchronously transmitting data across fibers in a serial manner. Frames are provided as a mechanism to transmit associated data serially and tie the data being transmitted to a particular buffer set. Each buffer set maintains a state that keeps track of the progress and sequence of received frames. When transmission errors occur in the frames, the errors may affect only the information field and there is enough information in the header to identify the frame. A request can then be sent back to the other end of the fibers to retransmit the frame. Certain information in the frame header is not used to identify the frame, but is used to control the transfer of frames and identify lost frames. When a frame information field is damaged by transmission errors, this header information is retained by the receiver of the damaged frame. Retaining this information at the receiver of the damaged frame frees the sender for storing it during the transmission of each frame.