Hi Conor, On Fri, Nov 03, 2023 at 12:50:53PM +0000, Conor Dooley wrote: > On Thu, Nov 02, 2023 at 03:37:20PM -0400, Ben Wolsieffer wrote: > A wider range of supported word sizes and some additional buffers, > implies that the F4 could be used as a fallback compatible. Does the > register map change incompatibly in the process of widening the FIFOs or > something like that? Yes, the F4 has a single bit to select 8 or 16 bit word size, while the F7 uses four bits to select an arbitrary word size from 4 to 16 bits. This series supports the packing mode, to allow sending two <=8 bit words with a single write to the FIFO, but even if we didn't want to support this feature, the F7 would require setting the FRXTH bit (not present in the F4) when using <=8 bit word sizes. > > Cheers, > Conor.