Hello everyone,
I've just realized a PCB using STM32H7A3 micro. But at second step I already fell.
I've my system powered up at 3.3V from an external circuit. The quality seems to be good.
I've tried to program the micro using STlink through a SWD port. The result is "No device found on target ".
I'm sure the setup works as I used it for programming the devlopement board STM32H745I-DISCO. In that case I've had no problem.
I've checked the signals on the PCB as far as reachable:
- Reset is pulled high
- Boot0 is pulled low
- VCC is stable at 3.3V and appears at all desired pins of the board
- GND is connected to all the necessary pins
- VDDA and VDDS are connected to 2,5V and GND
- PDR_ON is connected 3.3V
I suppose could be a matter of power supply so I started checking my configuration.
Here's my condition. I use an external regulator and I want to use only the internal LDO:
What's strange to me is that I expect to read something around 1,2V across the capacitors
connected to VCAP while actually there's nothing on it. So I wonder the LDO regulator
isn't working.
Does anyone have a suggestion on how to proceed?
Kind regards.
Matteo
