STM32H753I-Eval2 in DFU mode

TLuke.2 · ‎2024-01-31

Hello,

I'm curious if I am going through the correct procedure to put th H753I eval board in DFU mode. I have the power jumper JP10 on PSU. I then put a jumper on JP3 which is labeled BL_BOOT0 (which as far as I know puts the H7 in DFU mode when pulled high). I then plug in the PSU and then plug in usb cable to my pc and to the eval board. I've tried all three OTG ports, but I get no activity on my pc. When I check device manager, nothing new shows up at all. I've seen other see STM32 BOOTLOADER and STM32 in DFU mode, but I don't see either of these.

Any help or insight would be appreciated. Thank you.

Pavel A. · ‎2024-02-12

> DFU mode required flash memory to be completely blank.

Blank flash is NOT one of "patterns" which force booting from the built-in bootloader for STM32H753. The "patterns" for activation of system bootloader are documented in AN2606 section 4.1. So I suspect that the option bytes for the boot address were corrupted, and the full erase restored them to factory values.

TLuke.2 · ‎2024-02-15

So I've moved away from the eval board onto a custom board. I once again cannot get the pc to recognize any device when I put it in DFU mode via USB. I have pulled the BOOT0 pin high, and in fact if I then try to connect via USART, the bootloader works fine. I've verified the boot addresses are correct by inspecting the registers. The USB I'm connecting to is wired on pins PA11 and PA12 as per AN2606 in section "STM32H74xxx/75xxx devices bootloader" (I'm using STM32H753xx). When not trying to go into bootloader mode, I have been able to setup the USB in device mode and did a test with the mass storage class, connected to my pc and transferred files into the built in ram.

HOWEVER, my board is setup in a way that requires the USB power regulator to be turned on. I noticed this in AN2606: "DFU mode does not support USBREGEN mode. If STM32 is powered by 1.8 V source, it is
not possible to use the BL DFU unless 3.3 V is provided"

I had my engineer do a quick mod to jump over 3.3 to the USB so that it doesn't need the regulator, but I'm still having no luck. It is unfortunate that I cannot see the bootloader code in regards to the USB periph configuration to see if there may be other pitfalls I am missing.