the new board powered up OK and the debugger talks to the new STM32H7.

The H7 has more SAI ports

I'm using the 3rd port for the TI audio code for LTC timecode IO

The 4th port doesn't really configure in cubeMX as I've maxed out all the DMA channels !

my main mistake so far i can see is I don't have the XMOS I2C as slave connected up to the an i2C master on the STM32H7 in the way i was going to. somehow slipped through the net!  the only use i could think for it was to shut down the XMOS chip for power saving anyway when not using AVB gigabit audio and/or aes3 and/or usbC pc mac connectivity. I find it hard to believe that little XMOS will cope with doing all three AES3 / USBC / AVB simultaneously but it's wired up like that in case :)

I made a little 2.54mm 20pin -> 1.27mm 20pin connector convertor for the XMOS debugger to save board space.

I'm still waiting for the TI codec IC / gigabit PY chip / RF connectors and USB C connector. 

I'm pretty excited to be able to use the interface with a DAW over AVB or USB C.

In some ways it will be easier to test the analogue stuff without pulling the mico SD card out and inserting into the computer all the time !

One thing I should have included maybe is another USB socket to mount the micro SD cards from PC/MAC but i don't think that will be to hard to add in future revisions.

I need to also see if it's possible to add an SSD controller to an STM32H7. I imagine your moving towards having to run an operating system for that which i'm not really up for ! but if i can mount an SSD like the micoSD with a simple exFAT capable library in C then why not.

OK, lots of firmware work ahead after I update the analogue board and click together with the board to board connector :)

I will hopefully be able to reuse most of my code from stm32f7 but this time i'm using generated code from cubeMX and going to try adding my code in the user sections.. might be a trap ! herd horror stories of code being over written by cubeMX in user sections on forums so will have to make a lot of backups !