hi As mentioned in CGEN's manual, CGEN support GDB's sim as a simulator, but I don't know how to use GDB's sim, and I can't find any document which tell me how to use it. Is there any document about GDB's sim, or please tell me how to use it? In addition, as I know, GDB is a debugger, could it test the performance of a CPU or a systerm? In fact, that is my purpose to use CGEN && CGEN-based simulator! thank u for ur help! dam wang _________________________________________________________________ ÏíÓÃÊÀ½çÉÏ×î´óµÄµç×ÓÓʼþϵͳ¡ª MSN Hotmail¡£http://www.hotmail.com/cn