This month the entire STM32H7 series of high performance ARM microcontrollers has gotten a new revision "V" So whats so special about a little bit of a chip revision?
The first thing to notice is that the max CPU clock speed has changed from 400 MHz to 480 Mhz. This is not something that commonly happens with just a revision, but ST has already changed all of its specs and datasheets to reflect this:
https://www.st.com/en/microcontrollers-microprocessors/stm32h7-series.html#productsAll the chips in the STM32H7 series now claim 480MHz. The front page of the datasheet claims 480MHz (With no mention of the older 400MHz). But since the revision is brand new all chips you buy from Digikey, Mouser, Farnell/Avnet... etc will be the older 400MHz revision. They are all the same partnumber with no special sufix after it so when you buy any STM32H7 in the future it will be the luck of the draw if you get the 400MHz or 480MHz version (At least until all old stocks around the world are depleted).
But it doesn't stop there. There is a pretty hefty list of changes, enough for them to write app note AN5312:
https://www.st.com/content/ccc/resource/technical/document/application_note/group1/95/22/7c/0c/57/de/4b/f9/DM00609692/files/DM00609692.pdf/jcr:content/translations/en.DM00609692.pdfSome of the major changes are:
-Changes to the flash writing sequence
-Changes to the pinmux by adding extra alternate functions to pins
-Overhaul of a lot of USB controller registers
-ADC Now has a extra 'divide by 2' on its clock inside it, making existing clock configurations too slow
-Changes to the ADC registers (For example a value in a register that used to set the ADC to 8bit mode is now setting it to 'reserved' so likely doesn't work)
So quite a bit of existing firmware could fall on its face when run on the new revision chip. There own STM32CubeMX software that generates initialization code for you, has at the moment no way of telling it what revision chip you have so that it could set it up accordingly. Tho the HAL libraries did receive some updates for the new registers.
Call me picky but i think this is far too big of a change for a simple revision. The chip should at least get a extra suffix to the partnumber, how else do you make sure you actually buy the right one.