Cube IDE / STLINK V3SET / 32F4xx - 100% reliable, or not?

[peter-h]

I have just moved from ST-LINK/V2 ISOL to STLINK-V3SET.

The reason was to see if the SWV ITM debug mode was more reliable (or occassionally loses a byte or so), and I read somewhere that V3 is much faster.

Well, V3 is much faster. Code download has gone from a few seconds (~200k) to something so fast I can barely see it. This is worth having especially in a production environment, and especially at 24MHz (which is what it turns out to use if you select Auto)



But it isn't all that reliable. After some minutes Console says it has lost contact. At 8MHz it seems to be more reliable. I guess the quality of the wiring comes into it... I have about 30cm which is 20cm ribbon cable and 10cm single wires to my PCB. But even 8MHz is not 100% reliable. All speeds are 100% reliable for code download (well, it always reports as having verified) but in the long run with debugs it does eventually bomb out. I tried the debugger at 1MHz instead of 2MHz but it makes no difference.

I am using SWV ITM debug because it is very fast - see here for actual numbers
https://www.eevblog.com/forum/microcontrollers/cube-ide-32f4-breakpoints-and-dynamic-printf-etc/msg3552164/#msg3552164

Should I just accept that this stuff is a bit flakey and live with it? STLINK-V2 was rock solid in terms of the connection to the debugger, whereas V3 eventually loses the connection.

If anyone can suggest anything else for me to try I would be very grateful.

The other modes in the screenshot e.g. JTAG do not work, which is weird since JTAG is what this whole thing is supposed to be using. Only SWD works. The target connections are

JT-SWCLK
JT-SWDIO
NRST
JT-SWO
JT-NJTRS (no connect)