Initial Signal Condition

[AE104]

Hello,

I am using the STM32F767 microprocessor with Bluetooth control. A custom-designed user interface controls the system parameters such as updating the variables and receiving data. But when I power on the system, I flash the code. Then, in the first run of the system, I get a non-symmetric and offset added signal which is not set up like that (attached Figure CError_v1). Then in the second run, I got square signal with an offset voltage, and in the third run of the system, I got my clear signal. In ever run, I didn't change anything. What do you think that I got a strange signal initially? In addition, do I have flash every time the codes whenever powered off?

Thank you,

[Tesla DeLorean]

Got good bondings on all you grounds? No odd islands in the netlists where there were some name mismatches in the power symbols?

>>In addition, do I have flash every time the codes whenever powered off?

You should only need to flash the F767 once, if it's not starting properly make sure BOOT0 is pulled to ground, slow rise on the supplies with a floating BOOT0 pin often results in running from the System ROM. Watch also VDDA/VSSA, the POR circuits and PLL used these, not just ADC/DAC. Watch capacitor values and voltages on VCAP pins.

[AE104]

I have checked the ground connections but finished all of them. On the design, I recognized that the ground connections were connected to each other through the GND plane, not connected directly with traces. Does it cause this issue? I attached what I mean by sharing a small of the PCB layout.

I flashed the codes, and the BOOT0 is grounded every time. So, this is the ideal case, isn't it? In addition, the NRST is connected to the debugger connector. Does it cause this issue? @Community member​