Abstract: A simulation system includes glitch injection circuitry in one or more hardware design units to allow the injection of glitches or noise to evaluate the system's response to errors on signals between the hardware design units. The simulation system includes a stimulation module with a set of drivers to input simulation patterns into the design units. Some inputs to software models are driven by the outputs of software models of another design unit. The stimulation module can monitor these signals driven by the software model but it is difficult for the stimulation module to directly drive these signals. The added glitch circuitry allows injection of errors into the simulated hardware by the stimulation module on signals that are not directly driven by the stimulation module but are driven by the outputs of hardware design units.

Abstract: Process and apparatus for testing a microprocessor and dynamic RAM by a single tester where the microprocessor and dynamic RAM may be on a single card. The process makes the RAM appear static to an external static tester by separate read/write and refresh logic for the RAM. Two different clock generators connect to logic where each clock is selectively connectable to an on-board oscillator or to an external input. Priority logic for gating the refresh logic within a predetermined interval and gating the read/write logic at other times. The process includes three steps of a static logic test, a memory interface test, and, a functional test of the logic and the dynamic RAM. The third step is accomplished by executing a program in the on-card microprocessor. The three steps of the test form a single set of test data.