> I think the on-board spi nor flash support 104/108/133 mhz > so 50 mhz is wrong in any case. Thanks, I tested 104MHz on linux and it works fine. As for 133 MHz, only MX25U12835FZNI-08G supports it. And I didn't find it support 108MHz in the datasheet of MX25U12835F. Thanks, Chukun