Hi, I designed PCB including STM32F103CBT6 and I have attached schematic here as a reference. I am using SWD with an adapter from (Olimex LTD / ARM-JTAG-20-10) then connect through ST-LINK/VE debugger. After checking all voltage rails on the board, I used ST-Link utility tool to check the connection between the board and computer. However I am having issue here.
When I click target then connect on the utility tool, I see this following error (Also attached here as error1)
"Can not connect to target! If you're trying to connect to an STM32W1xx device, please select normal or hotplug mode from target ->setting menu. If you're trying to connect to a low frequency application, please select a lower SWD frequency mode from target->Setting menu". With this error popped up, I see the power supply of mcu (3.3V) is jumped to almost 50mA from 8mA, so I had to disconnect USB from computer and debugger. I made sure all connections are correct. I tried connecting USB back and try again but I see same behavior.
Then I tried to erase chip function on utility tool then target connect. I see debugger toggle RED/GREEN LED and see that connection is established on the utility tool. It recognizes the mcu, id number and etc. Also power supply current is remained the same. So I unplugged USB then plugged back the USB to the computer. I tried to target -> connect. I don't see any issue again. It recognizes the mcu.
What is happening here? Why did erasing chip function on the utility tool suddenly make the connection successful? Also does it make sense to see all register value being 1's(FFFF) after erasing chip function?
Any comments would be appreciated. Thank you