I own a proprietary design based on STM32H743ZGT6.
Two boards were assembled.
Initially both boards work identically.
After about two days of software bring-up activity on one board following issues were encountered:
1) Debug through JTAG is not possible, console log:
Target unknown MCU target
Error in initializing ST-LINK device.
Reason: Unknown MCU found on target.
Debug through SWD is still possible.
2) Voltage level at BOOT0 pin no longer affects the processor booting - always booting from Flash is performed.
3) GPIO Port E behaves so that no external signals can be probed by the core (always 0 is read from the IDR) and no external signals can be driven - always tristate (though MODER and ODR contents can be altered).
Other GPIO ports are operational.
On the second board GPIO Port E successfully drives a LED and is used to read levels of five external signals. The same works identically on the problem board before the failure.
Is it possible to provide some insight by analyzing the silicon internal structure?
Best regards,
Fedor
