This previous thread refers
https://community.st.com/t5/stm32-mcus-products/stm32f4xx-does-going-up-a-package-pin-count-impact-pin-af/td-p/862282
The 437 is curiously a very close superset of the 417. Apart from the extra 64k RAM, the only difference is which ADC channel is used to read Vbat. And of course the device ID is changed. This makes the 437 a very easy and useful upgrade from the 407/417.
My Q is whether AF mapping is really identical, so that a 417 project can access the additional 437 peripherals (e.g. SPI4,5,6) by going to a larger pin count package.
Comparing the data sheets, it does not appear that the 437 gives you any new peripheral access without going to a larger package i.e. it does not offer any new AF flexibility. For example you cannot access SPI4-6 on the QFP100.
I am using the 437 for the extra 64k RAM. I check the device ID. This is 0x413 or 0x419 for the 417 or 437. If I detect the 437 I move the general stack 64k higher and fix up the Vbat measurement.
