cannot produce a value in Device Memory with the warning
Hello everyone I would like to ask about a warning on my STM32 hardware. I'm using an STM32F405 board that I designed myself. I use NUCLEOf334 as the debugger (ST_LINK). I make sure that I have removed all the jumpers on the nucleo so as not to interfere with the MCU on the nucleo. Now the problem is that when I use the debugger on the board that I have designed STM32f405, I check the ST-LINK with "Connection mode : Connect Under Reset" mode and it cannot produce a value in Device Memory with the warning
"10:47:27 : Can not connect to target!
If you are trying to connect to the STM32W1xx device, please select Normal or HotPlug mode from the Target->Settings menu.
If you are trying to connect to a low frequency application, please select a lower SWD Frequency mode from the Target->Settings menu.
10:47:29 : Core is hold in reset"
The picture above is an explanation that after I tried the "Hot Plug" I was traumatized by connecting, because I had damaged 2 boards just because of this problem.
but I've tried the results in Device Manager, all 0. I've checked the voltage coming out of my MCU, all 3.5 v, it should still be safe, right? I wonder what the problem is.I know this is a hardware problem but I'm stuck, maybe you have experienced the same thing??