hi. I know GDB use software breakpoint. What operation happens in mpc860 when setting of breakpoint by software ? I mean what register is used for setting instruction breakpoint or something else? thank you. Nohee Ko Staff Engineer, SI Hardware www.gctsemi.com Tel. 82-2-2167-1283 Fax. 82-2-2167-1290 Mobile : 016-368-7742