I am trying to designed a product using the RT1062. I am using the teensy 4.0 for a EVBs. In my product I need two uC to communicate with one another in a speed of 400 MHz, an I want to use the flexSPI peripheral. I am using NXP SDK and MCUXpresso for writing the code.

I am having difficulty using the flexSPI and configuring one of the Teensy 4.0 as slave.
Has anybody done this before? If so how?
Does anyone have a suggestion to how I can achieve the communication speed I am seeking?