[ell-i-developers] STM32 SWD debugging and sleep

  • From: Teemu Hakala <temmi@xxxxxx>
  • To: ell-i-developers@xxxxxxxxxxxxx
  • Date: Tue, 25 Feb 2014 06:47:53 +0200

Hi all

Just recently I was pointed to information about special requirements that a 
SWD debugging session poses on STM32 sleep modes, especially some clocks.

Apparently the clocks discussed are absolutely necessary by SWD/JTAG hardware 
and cannot be turned off during the debugging session. This naturally means 
that some of the sleep potential is lost but mostly that sleep mode debugging 
can be nonintuitive. In this and many other cases using some output pin to flag 
events or states is better, those can be then captured on oscilloscope or 
visually by led. This then is very close to printf()ing stuff to STDERR for 
debugging purposes.

I know we’re not yet enabling any sleep modes so this is premature and as such 
is mostly entertainment. No need to act or remember, it’ll pop up in someone’s 
mind when we’re about to need sleep modes.


This all of course is in the reference manual, but this is result of someone’s 
learning session and put in a very practical format.

RuuviTracker is a small STM32F4+GSM+GPS+MEMS -board for developing small very 
mobile applications with eLua scripting.

 - t

Other related posts:

  • » [ell-i-developers] STM32 SWD debugging and sleep - Teemu Hakala