Abstract: This invention is time stamping subsystem of an electronic apparatus. A time stamp generator generates a multibit time stamp value including a predetermined number of least significant bits overlapping a predetermined number of most significant bits. Each client receives the least significant bits. Each client associates captured data with a corresponding set of the least significant bits in a message. A central scheduling unit associates most significant bits of the time stamp value with the least significant bits of the message. This associating compares overlap bits of the most significant bits and least significant bits. The most significant bits are decremented until the overlap bits are equal.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: A system and method for sharing a communications link between multiple protocols is described. A system includes a communications interface configured to exchange information with other systems using at least one of a plurality of protocols; a protocol select register that stores a value that selects a protocol from among the plurality of protocols to become an active protocol; and a state machine accessible to the communications interface, the state machine used to control the exchange of information through the communications interface according to the active protocol. The active protocol is used by the communications interface to exchange information while the remaining protocols of the plurality of protocols remain inactive. The state machine sequences through a series of states that cause the communications interface to operate according to the active protocol, and that are designated as inert sequences under the remaining protocols.

Abstract: Topology discovery of a target system having a plurality of components coupled with a scan topology may be performed by driving a low logic value on the data input signal and a data output signal of the scan topology. An input data value and an output data value for each of the plurality of components is sampled and recorded. A low logic value is then scanned through the scan path and recorded at each component. The scan topology may be determined based on the recorded data values and the recorded scan values.

Abstract: A method is shown to provide remote access to one or more debug access points whose functions include capabilities other than accessing memories across an application interface such as USB, IEEE 802.3 (Ethernet) and other protocols. The capabilities available include all or many of the capabilities provided by a dedicated debug interface.

Abstract: Control events may be signaled to a target system having a plurality of components coupled to a scan path by using the clock and data signals of the scan path. While the clock signal is held a high logic level, two or more edge transitions are detected on the data signal. The number of edge transitions on the data signal is counted while the clock signal is held at the high logic state. A control event is determined based on the counted number of edge transitions on the data signal after the clock signal transitions to the low logic state.

Abstract: The invention is a method of operating a system having multiple finite state machines and a controller. Each finite state machine enters an offline state upon detection of anomalous operation. The controller detects whether all finite state machines are offline. The controller transmits an online activation event signal to each finite state machine when all are offline. Each finite state machine evaluates entering the online state if current conditions permit. Reentering the online state includes loading a predetermined set of operating parameters. The finite state machines are responsive only to a reset event and an online activation event when in the offline state.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: A method of detecting lost data within a data stream by inserting sequence numbers within the stream. Network data blocks to be transmitted are assembled from data chunks, where each data chunk contains a sequence number. Where the data is originating from multiple sources, the sequence numbers are labeled with an unique source ID, and are inserted into the composite data stream after one or more data chunks are generated.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: A self clocking data extraction method is shown that is tolerant of timing jitter, data skew and the presence of multiple edges per data bit. The data is sampled when the following criterion are met: There is at least one edge across any track (the clock assures this criteria is met), followed by no edges in any track for a defined period of time (T), and all edge activity must occur in a period of time less than T (to keep from detecting false samples). This method enables the handling of trace data signals with poor electrical characteristics that can not be recorded by methods known in the prior art.

Abstract: Control events may be signaled to a target system having a plurality of components coupled to a scan path by using the clock and data signals of the scan path. While the clock signal is held a high logic level, two or more edge transitions are detected on the data signal. The number of edge transitions on the data signal is counted while the clock signal is held at the high logic state. A control event is determined based on the counted number of edge transitions on the data signal after the clock signal transitions to the low logic state.

Abstract: A system and method for sharing a communications link between multiple protocols is described. A system includes a communications interface configured to exchange information with other systems using at least one of a plurality of protocols; a protocol select register that stores a value that selects a protocol from among the plurality of protocols to become an active protocol; and a state machine accessible to the communications interface, the state machine used to control the exchange of information through the communications interface according to the active protocol. The active protocol is used by the communications interface to exchange information while the remaining protocols of the plurality of protocols remain inactive. The state machine sequences through a series of states that cause the communications interface to operate according to the active protocol, and that are designated as inert sequences under the remaining protocols.

Abstract: A method of detecting lost data within a data stream by inserting sequence numbers within the stream. Network data blocks to be transmitted are assembled from data chunks, where each data chunk contains a sequence number. Where the data is originating from multiple sources, the sequence numbers are labeled with an unique source ID, and are inserted into the composite data stream after one or more data chunks are generated.

Abstract: Topology discovery of a target system having a plurality of components coupled with a scan topology may be performed by driving a low logic value on the data input signal and a data output signal of the scan topology. An input data value and an output data value for each of the plurality of components is sampled and recorded. A low logic value is then scanned through the scan path and recorded at each component. The scan topology may be determined based on the recorded data values and the recorded scan values.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: A method comprises a system comprising a host device coupled to a first remote device actively operating according to a state diagram that the host device and all remote devices follow during operation of the system. The method further comprises powering up a second remote device while the host device and first remote device are actively operating according to the state diagram. The second remote device waits for a synchronization point sequence. Upon detecting the synchronization point sequence, the second remote device implements a predetermined feature set and synchronizes itself to the state diagram at a common point as the host device and first remote device.

Abstract: A system and method for sharing a communications link between multiple protocols is described. A system includes a communications interface configured to exchange information with other systems using at least one of a plurality of protocols; a protocol select register that stores a value that selects a protocol from among the plurality of protocols to become an active protocol; and a state machine accessible to the communications interface, the state machine used to control the exchange of information through the communications interface according to the active protocol. The active protocol is used by the communications interface to exchange information while the remaining protocols of the plurality of protocols remain inactive. The state machine sequences through a series of states that cause the communications interface to operate according to the active protocol, and that are designated as inert sequences under the remaining protocols.

Abstract: A method for easily tracing the execution of an application in a computer system having a plurality of computing nodes interconnected by high speed data links is disclosed. While executing the application on one or more of the computing nodes, trace data is collected into a separate temporary trace buffer coupled to each computing node. A trace transfer request event may be generated after collecting a portion of the trace data. The trace data is recorded on a designated recording and analysis computing node by transferring the trace data from each trace buffer to a recording buffer in the designated recording node in response to the transfer request by performing memory mapped write transfers initiated by each computing node that has collected trace data. The address of the recording buffer is memory mapped into an address space of each computing node that has collected trace data.

Abstract: A system having a plurality of application computer circuits is disclosed. A first application computer circuit is arranged to process a first application. A trace collection circuit collects trace information from the first application computer circuit. A second application computer circuit is arranged to receive and store the collected trace information in a first mode and to process a second application in a second mode.