Debugging prototype PCB design using 7 stm32n647l0h3q microcontrollers. Not able to get chips to boot and reply to queries. Would like suggestions on possible issues and solutions.
We might need to look at both the board layout and the schematic. Can you provide this?
We suspect the design has an incorrect connection to Boot Pin 1, but we rework connected the 0 to 3.3V and 1 to GND as per spec for UART boot and the chips still will not respond to data input.
STM32single 05 04 2026 for upload.pdf (639.9 KB)
Schematic for the single STM32 and notes attached.
We have procured a dev board for a STM32N657 and it is behaving similar to our 647 chips on our board when we try to boot and program.
Also, is there someone who is an expert in these microcontrollers that we could have a call or chat meeting with?
That would be our Engineer @Matt_Mielke he typically monitors this forum and responds here. I’m bringing this to his attention.
Thank you! Much appreciated.
Hello @EugeneV,
- Which dev board are you using?
- What do you mean by “similar”?
- How exactly are you attempting to communicate with the board(s)? Please outline your procedure in full detail, such that I might be able to replicate it.
Hi Matt,
Let me hand these questions off to our EE. I am just helping support him.
Eugene
Answer 1: the model dev board we have is STM32N6570-DK
Eugene
Response from our EE:
We are using MB1939C (DK32N6570$CR1)
Connection:
Removed pins PA9, PA10 from other circuitry (removed resistor at SB51, lifted pins 6,7 of U8.)
After power-on and also tried NRST button, sending 0x7F afterward (tried both 9600 baud and 115200 baud)
TX output is always at zero (unless pulled high with resistor).
Connected series resistor to check for collision, same result.
Swapped TX and RX with series resistors, same result.
Our HAT / board design was connected in the same manner with same results.
Can the STM32N647 version be connected and programmed through UART? That seems to be the crux of our problem.
Yes, the boot ROM supports serial interfaces including USART1, USART2, and UART4.
It sounds like you’re trying to implement the protocol manually… what are you using as your programming tool? Is the host device setup to be compatible with the following?
Have you tried using STM32CubeProgrammer???
Here’s the documentation I’m referencing on my end, just to make sure we’re on the same page: