Dear all, altough i selected the correct target device and clock speed, i see that the Oregano IP core takes the same amount of time for one operation like an original 8051. In fact, the Oregano systems IP core does most of the instructions in one clock cycle whereas they take 12 clock cycles on an original 8051 controller. Since the timers work correctly, it is hardly possible to simulate anything. Did i ignore any settings? Thanks and best regards, Tobias