2021-10-26 02:27 AM
I'm using VSCode/Debug-Cortex with STLink V3Mini. The target is a board with STM32H743VI and SWD. The board has only basic swd with GND, 3V3, SWDIO, SWCLK. There is no reset line, unfortunately also not on other headers.
When I start debugging, the debug probe connects and loads some stub to flash. After that, it tries to reset again, but this fails. It works only when I solder connect a reset line and cube programmer can perform a connect under reset.
STMicroelectronics ST-LINK GDB server. Version 5.8.0
Copyright (c) 2020, STMicroelectronics. All rights reserved.
Starting server with the following options:
Persistent Mode : Disabled
Logging Level : 31
Listen Port Number : 50000
Status Refresh Delay : 15s
Verbose Mode : Disabled
SWD Debug : Enabled
Target connection mode: Default
Reading ROM table for AP 0 @0xe00fefd0
Hardware watchpoint supported by the target
COM frequency = 24000 kHz
ST-LINK Firmware version : V3J7M2
Device ID: 0x450
PC: 0x80037fc
ST-LINK device status: HALT_MODE
ST-LINK detects target voltage = 3.29 V
ST-LINK device status: HALT_MODE
ST-LINK device initialization OK
Waiting for debugger connection...
Waiting for connection on port 50000...
Accepted connection on port 50000...
Debugger connected
Enter STM32_AppReset() function
NVIC_DFSR_REG = 0x0000000B
NVIC_CFGFSR_REG = 0x00000000
------ Switching to STM32CubeProgrammer -----
-------------------------------------------------------------------
STM32CubeProgrammer v2.8.0
-------------------------------------------------------------------
ST-LINK SN : 004900313137510B33333639
ST-LINK FW : V3J7M2
Board : STLINK-V3MINI
Voltage : 3.29V
SWD freq : 24000 KHz
Connect mode: Under Reset
Reset mode : Hardware reset
Device ID : 0x450
Revision ID : Rev V
Device name : STM32H7xx
Flash size : 2 MBytes
Device type : MCU
Device CPU : Cortex-M7
BL Version : 0x90
Memory Programming ...
Opening and parsing file: ST-LINK_GDB_server_a16228.srec
File : ST-LINK_GDB_server_a16228.srec
Size : 40704 Bytes
Address : 0x08000000
Erasing memory corresponding to segment 0:
Erasing internal memory sector 0
Download in Progress:
File download complete
Time elapsed during download operation: 00:00:00.988
------ Switching context -----
Target connection mode: Default
Target connection failed. Try connecting under reset
Target connection failed
Target no device found
is it possible to connect also in normal mode, without reset line?
2021-10-26 09:08 AM
For an off board connection, try to lower "COM frequency = 24000 kHz" or provide substantial more ground connections.
2021-10-26 12:55 PM
thanks Uwe,
flashing and debugging works reliable, its only the reset line. When I tried the connection in the command line, I could see also that STM32CubeProgrammer tries to connect with lower speed by itself.
The problem is almost cosmetic, the extra wire is not looking nice. And its for my curiosity.