Help understanding mysterious lapses in printf() output via SWV Port 0 as shown in SWV ITM Data Console

[Ted Jackson]

Notice how entire printf lines disappear and how occasionally just portions of printf lines disappear.

[Tesla DeLorean]

There are buffering issues within the pod

[Ted Jackson]

Even if I include fflush(stdiot); immediately after the printf, the problem is the same.

[Pavel A.]

Well there are many layers that can cause this. From the ST-LINK firmware up to the host ST-LINK or OpenOCD server, to the CubeIDE (Eclipse) debugger client.

Has anybody seen these glitches with true J-Link adapters?

--pa

[Tesla DeLorean]

Presuming this is an ST-LINK?

Does fflush() have any plumbing?

You could try the SWV screen of STM32 Cube Programmer or ST-Link Utilities and see if that is more robust

As @Pavel A.​ notes there are a lot of moving parts here, a J-Link Ultra+ might work significantly better but we're in a whole different league there.

[Ted Jackson]

It's an ST-LINK.