STM32F400CBT6 is not found in the list of ST microcontroller. I've bought it from LCSC. It's datasheet is found in LCSC only that is also in Chinese only. I am not able to program it using stlink. The schematic I used to program is as shown. How can I program it? When I try to program it, the stlink programmmer does not detect the ic. Have I done something wrong it the schematic or this ic need another way to program?
Well, it's listed on ST's Chinese website. But not in English. I guess they're doing market segmentation.
Some questions in their forums about building a project suggested building for a STM32F410CB but I don't think that solves your problem.
May I know the reason behind connecting all the VDD/VSS pins although they are internally connected?
The internal connections not only have "continuity" but also have parasitic series impedances that a simple multimeter won't help you measure.
The fact that there are internal connections is an implementation detail. You must operate as if those connections weren't there. Otherwise you can damage the chip, or make it misbehave. Never skip any power nor ground pins - they must all be appropriately connected!!
