We are using flexspi bus to read data from FPGA. with iMX RT 600 MHz processor. We have found out the access to the plexspi control registers is very slow. We have measured 60 nano seconds for reads and the same for writing. For example
base->ISR = mask;
takes 60 ns and we would like to know if this is what it takes to communicate from 600 MHz bus to the much slower 150 MHz bus or may be we haven't configured correctly our device?