BCLK Frequency

As far as I can tell from the manuals, BCLK is fixed at 75MHz (i.e. the AHB bus clock frequency) assuming 150MHz CPU speed.

Has anyone found a way to output a lower fequency on this pin without slowing down the CPU? I really don’t want (or need) 75MHz floating around my board.

I don’t believe this is possible without doing a chip design