The Device Driver Test Tool (DDTT) provides an efficient environment to create, execute, and refine device driver test cases. The DDTT is extensible by the addition of new device-dependent DLLs and grammar files. DLL files implement device-specific interface functions, such as DosDevIOCtl calls. Actual test-case content and execution is controlled by test-case script files.

Test-case script files are parsed by DDTT's generic parser. Device-specific functions resident in the DLLs are indirectly called from the test-case parser. Device-specific grammar files tell the parser which device-specific function and parameter keywords to expect in the test-case script files.