Posted on October 21, 2016 at 23:12I have a few questions about the hardware debug support.
1) Is there a way for software to detect and active SWD connection ?
2) Any examples of using the debug monitor exception ?
We're building some small data loggers and plan to use the SWD interface to configure and download data. The first question relates to using breakpoint instructions to signal the swd debugger -- if one is not connected, we want to skip the bkpt. (2) seems to offer a way for the debugger hardware to signal the device.
I've had good luck using the st-util library to attach to a device and access the processor state -- even execute routines in the processor's memory. But, I'd like to do something a bit more principled.
------- Edit ----
I found the answer to most of my questions -- yes a running program can tell it a debugger is attached through the
C_DEBUGEN
bit in the Debug Halting Control and Status Register DBCSR.
It looks like a custom ''debug monitor'' is the way to go for what I want to do. I can certain enter the debug monitor through polling. Still trying to understand how to thave the st-link trigger a debug monitor interrupt -- seems doable, but I haven't tried yet.
