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Can i set a LED output register on DISCOVERY board with SWD.

Question asked by Patrick Morwald on Jul 11, 2017
Latest reply on Jul 13, 2017 by Imen D



i wondered if i can use the #SWD in #ST-Link on the STM32F407G-DISCO1 Board to set individual IO registers during runtime?


According to ARM specification of SWD it can be used as AMBA bus master to manipulate IO registers...


So consider the simple test case: I want to switch on the red onboard LED (PD14) on the DISCOVERY board with SWD during runtime. How do i do it? What client software would you recommend? 


I tried SW4STM32 but couldnt write the IO registers during runtime, no idea why it did not work.


I also used ST-LINK CLI and read memory address 0x40020C00 - 0x40020FFF (GPIO D memory area) but i only got zeros....


Am i using the SWD in the wrong way? Please help!