One aspect of the invention relates to a method for detecting architectural violations in a multiprocessor computer system. In one version of the invention, the method includes the steps of generating a testcase instruction stream having a plurality of instructions, executable by the processors, which access a memory which is shared by the processors; detecting dependent instructions in the testcase instruction stream; and modifying the testcase instruction stream by inserting logging instructions in the testcase in the testcase instruction stream which cause data associated with observable instructions to be written to a logging memory by writing a first sequence of unique monotonically increasing values to the memory. Thereafter, a second sequence of values is read from the memory location and a window of observed values is defined, wherein the window has a highest observable value and a lowest observable value where the highest observable value is set to the highest value of the first sequence and the lowest observable value is set to the lowest value of the first sequence and wherein the lowest observable value is updated with a next observable value from the first sequence whenever the value of an individual read from the second sequence is higher than the lowest observable value so that a determination can be made whether individual values in the second sequence are within the window.
A system for maintaining data coherency. The system includes a plurality of processors. A plurality of resources is also included. One portion of the resources is sharable with the plurality of processors and each one of the other ones of the resources being dedicated to a predetermined one of the processors. The system also includes a plurality of buffers. Each one of the buffers is associated with a corresponding one of the plurality of processors. Each one of the buffers is adapted to successively store information presented thereto in successive locations of such one of the buffers. The information includes requests from the corresponding one of the processor. The system includes a logic section responsive to each one of the requests provided by the plurality of processors. The logic section produces indicia indicating whether or not such one of the requests is a request for an operation with one of the sharable resources. The logic section inserts the indicia into a succeeding one of the locations of the buffers associated with such one of the processor providing such one of the requests. The logic section also simultaneously inserts such indicia into a next succeeding available location of the other ones of the plurality of buffers. The logic section inhibits execution of requests in the buffers stored in locations thereof succeeding the location having stored therein any such inserted indicia.
A method for testing the correct behavior of an integrated circuit includes forming a list of potential data sharing locations, collecting memory access statistics of the potential data sharing locations, and forming subsequent test case threads to test specialized processing conditions of the integrated circuit based on the memory access statistics of the potential data sharing locations.
Methods and systems for automated memory test modeling generation and validation are provided. Information supplied by a graphical user interface is used to generate a customized memory primitive. The memory primitive subsequently undergoes a two phase validation to test for correct functioning.
The present invention provides a method and apparatus for design verification. The method comprises operating a device in the system in a first state, modifying at least one operational characteristic of the device to operate in a second state, and determining if an error condition occurs in the system in response to modifying the operational characteristic of the device. The apparatus comprises an interface and a verification module adapted to receive a control signal from the interface and to adjust an operating characteristic of the apparatus to exercise a system in a manner that is capable of revealing one or more error conditions in the system in response to receiving the control signal.
A method of operation within a processor that permits load instructions following barrier instructions in an instruction sequence to be issued speculatively. The barrier instruction is executed and while the barrier operation is pending, a load request associated with the load instruction is speculatively issued. A speculation flag is set to indicate the load instruction was speculatively issued. The flag is reset when an acknowledgment of the barrier operation is received. Data that is returned before the acknowledgment is received is temporarily held, and the data is forwarded to the register and/or execution unit of the processor only after the acknowledgment is received. If a snoop invalidate is detected for the speculatively issued load request before the barrier operation completes, the data is discarded and the load request is re-issued.
