Abstract: An apparatus, and a corresponding method, are used for testing a computer microarchitecture. The apparatus includes means for providing reprogrammed microcode. The means for providing the reprogrammed microcode includes means for reprogramming microcode, and means for storing reprogrammed microcode. The storing means includes microcode related to one or more macroinstructions, and reprogrammed test microcode for testing the computer microarchitecture, where the reprogrammed test microcode includes a sequence of microinstructions executed to test the computer microarchitecture. Finally, the apparatus includes means for sequencing the sequence of microinstructions and producing an address for the reprogrammed test microcode.

Abstract: An apparatus and a method of testing computer microarchitectures has a test writer create a test sequence written directly in microinstructions (both native-mode and emulation-only microinstructions). The microinstruction sequence is then inserted into a reprogrammable microcode storage, replacing the normal sequence of microinstructions for a given macroinstruction. In order to execute the microinstructions, the test writer can issue the macroinstruction. The method may be implemented in a simulation model where one set of microinstructions in the reprogrammable microcode storage can be easily replaced. The method may also be applied to an actual microprocessor implementation.

Abstract: A method and an apparatus for re-creating a trace of instructions from an emulated instruction set when running on hardware optimized for a different instruction set, such as IA-32 instructions running on an IA-64 machine, are disclosed. An execution trace buffer is created that maintains desired information about instructions as they are executed and retired. The invention may be configured such that certain desired information helpful to debugging the system may be written to the buffer as the instructions are retired. This information may include the addresses of sequential or branch instructions, or other relevant information that can be gathered continuously and non-intrusively as instructions are executed. The information may be read from the buffer and output in a machine-visible form at the user's convenience.