Hello,

I have a custom board with an STM32F407VE controller. I use my JLink for debugging and programming over SWD.
I'm using a Linux operating system with the newest released JLink software pack (6.62a-3).

I wanted to completely erase the device, so I opened JLinkExe. typed connect, device = STM32F407VE, connection interface = SWD
Everything went smoothly.

However, when I try to erase the chip by using the "erase" command, I get an Error:

Failed to prepare for programming.
RAM check failed @ addr 0x20000AB8
RAM check failed while testing 0x2050 bytes @ addr 0x2000006CC
ERROR: Erase returned with error code -1.

Trying once again and it works... Slowing down the SWD clock speed from 4 MHz to 1 MHz did not help.
I tested it out and it seems I've got about a 40% chance of it failing.

I don't understandy why I get this error. Debugging and programming work fine. I even used Ozone to capture some data over hours from my target. So the SWD connection seems stable.
Can you help me with this?

Thank you

I wired myself up to a STM32F4 discovery, which has almost the same Chip (STM32F407VGT6 instead of ...VET6) and the issue is still present.
I have no problems at all with programming (either over gdb + GDB Server, or over Ozone) everything works fine.

I've attached a full log. I executed the erase command 2 times. The first time it didn't wok. The second time was fine.