I'm trying to reduce the time taken to connect the debugger and halt the Cortex M3 core as much as possible. I see delays between JLinkScript calls that I think are down to the DLL interpreting the script on the fly. The SEGGER Wiki page about JLinkScript mentions pre-compiled pex files - does anyone know anything about creating these compiled binary files? Is this only a format internal to SEGGER?

Cheers

Thanks for the confirmation.

I have a custom ASIC with the potential for the SWD lines to be re-configured as GPIO when the ARM starts executing code. We can reduce the chance of this happening in code but it'll be a possibility to a degree. I'm trying to see how fast I can connect and halt by having my JLink script reset function perform a hard reset (via the JTAG 20-pin RESET pin) then wait for a successful CORESIGHT_Configure() call before asserting the S_HALT & S_DEBUGEN bits in the ARM core. I'm building in a pre-initialisation delay into the apps which will allow this halt process to complete before any chance of an SWD line being re-configured after main() is called. The smaller the initial required boot delay the better.

We can live with a long enough delay for now, and will contact SEGGER if we need faster script execution time in future. I do have a related question:

If the JLinkScript function JLINK_CORESIGHT_Configure() fails to configure, does it toggle the RESET line before it completes? I was hoping to call this function in a loop after the hard reset but can see a 50ms RESET period each iteration of the loop. I can't see any mention of this RESET toggle in the documentation, and was hoping it would just attempt a serial line reset followed by a switch to the SWD protocol each time it was called.