I have a custom board using K22FN1M0AM12 that I am trying to implement USB Host MSD on. I am using KDS v3.2.0 with Processor Expert v3.0.2. I am not using any RTOS. I used the example "USB_MSD_HOST_K60_PEx" as a starting point. I am using the "USB_HOST_STACK" processor expert component that is also used in that example with the same configuration.
I call the function "msd_host_init()" to initialize and get a success and then have an 8ms timer that calls the "Poll()" and "MSD_Task()" functions. When things are initialized I insert a USB stick (I have tried a few different types), and I eventually found that in the KHCI function "_usb_khci_task()" the "tick" count is reaching the defined max "KHCI_TICK_WAIT" and setting the response as NAK and never moving on. I have varied the interrupt priority for USB_LDD, changed the define "KHCI_TICK_WAIT" to a larger value, and some other things.
I should also mention that I run the uTasker USB Host MSD bootloader on this board with success so I know the hardware is correct