bringing up new STM32H734II board and no debugger

[Rhodes.Keith]

Posted on June 01, 2018 at 23:20

Hi,

This is a new custom board with the STM32H743II MPU with a Segger jlink debugger. Segger continually says that it cannot connect.

I have tried connecting with both SWD and JTAG, but same result.

All other comments are about SWD mode. We have checked SWDIO and SWCLK and all look fine. I see the bit pattern going down SWDIO correctly.

We have validated VDD at 3.3V, 1.1V on VCAP1 and 2. All VDD and VSS pins are connected correctly.

NRST toggles before SWCLK starts.

JRST is always high.

We have also successfully used the STM32H743ZI part in a different custom board and it works properly.

We have tested this with the latest Segger software (V6.32d).

Does anyone have any experience with this package? Have you ever heard of package-specific problems?

Any help would be appreciated.

Thanks...Keith Rhodes

#stm32h743

[Tesla DeLorean]

Posted on June 01, 2018 at 23:40

I've seen issues where people have misoriented devices. Issues with parts using PDR_ON. What package?

The other method to do signs of life is to strap BOOT0 high, and talk to one of the System Loader supported USARTs, sending 0x7F at 9600 8E1 and checking for the 0x79 response byte.

Most of the time if SWD/JTAG isn't working the wrong pins are being used or the critical logic is unpowered, or clamped in reset.

[Rhodes.Keith]

Posted on June 05, 2018 at 13:10

It turns out it was a problem with the *first* board. The second worked. Have to get back and figure out what was wrong with the first. Thanks.

[T J]

Posted on June 05, 2018 at 14:19

I use to hand place the parts myself, I use LQFPs for that reason.

and cook the board in a toaster oven.

but I never attempted to use a BGA part. just too easy to cross pins. Did the chip get hot ?

how did you make your board ?