I generate the clock and reset signal and input to the IP. After setting the global_reset_n high, the IP set the afi_reset_n low after 15 afi_clock. And set the mem_reset_n low after more 2 afi_clock. But the IP won't set the mem_reset_n high to start initialization. (The IP example will set mem_reset_n high almost at 16 us) Can someone give me some suggestions? Thank you.