Abstract: A circuit arrangement and method detect external requests to access a memory array in a hardware simulation accelerator during performance of a simulation on a simulation model and access the memory array without halting the simulation in response to detecting the external request. Such functionality may be provided, for example, by detecting such external requests in response to processing a predetermined instruction in an instruction stream associated with the simulation model, where the predetermined instruction is configured to ensure a predetermined period of inactivity for the memory array. By doing so, the memory array can be accessed from outside of the hardware simulation accelerator during the processing of a simulation, and without requiring that the simulation be halted, thus reducing overhead and improving simulation efficiency.

Abstract: A hardware accelerator includes hardware support for a combinational only cycle and a latch only cycle in a simulation model with a single partition of latches and combinational logic. Preferred embodiments use a special 4-input 1-output function unit in the hardware accelerator in place of the normal latch function that write back the old latch value for combinational only cycles. Other embodiments include hardware support for separate array write disables for arrays and transparent latches depending on whether the cycle is a combinational only cycle and a latch only cycle. A conditional array write disable dependent on the occurrence of a hardware breakpoint is also included that supports switching from a latch plus combinational cycle to a latch only cycle, to give control to the user before evaluating the combinational logic if a breakpoint occurs on a latch.

Abstract: A method and system are described in a logic simulator machine for efficiently creating a trace of an array which includes a plurality of storage locations. The logic simulator machine executes a test routine. Prior to executing the test routine, an initial copy of all data included within each of the storage locations of the array is stored as a first trace of the array. During execution of a first cycle the test routine, all of the write control inputs into the array are read to identify ones of the storage locations which were modified during the execution of the first cycle. A new trace of the array is generated which includes a copy of all of the data of the first trace. In addition, only those ones of the storage locations in the first trace which were modified during the first cycle are updated. A trace is thus generated by updating only those ones of the storage locations which were modified during execution of a cycle of the test routine.

Abstract: A method and system are described in a logic simulator machine for efficiently creating a trace of an array which includes a plurality of storage locations. The logic simulator machine executes a test routine. Prior to executing the test routine, an initial copy of all data included within each of the storage locations of the array is stored as a first trace of the array. During execution of a first cycle the test routine, all of the write control inputs into the array are read to identify ones of the storage locations which were modified during the execution of the first cycle. A new trace of the array is generated which includes a copy of all of the data of the first trace. In addition, only those ones of the storage locations in the first trace which were modified during the first cycle are updated. A trace is thus generated by updating only those ones of the storage locations which were modified during execution of a cycle of the test routine.