There are cheap clones of simple CMSIS-DAP interfaces from China.
They support ARM SWD and UART I/O when they actually work which is a rare occurrence. I gave up with it now.
They are unable to reset the target which may be a problem when the target is in sleep mode.
These devices may not work on some unpowered hubs since they demand 500mA current.
NB Always wire the ground wire even if you think you do not need to.
# wch.cn WCH-Link CMSIS-DAP (clone) SUBSYSTEMS=="usb",\ ATTRS{idVendor}=="2a86",\ ATTRS{idProduct}=="8011",\ MODE:="0666" KERNEL=="ttyACM*",\ ATTRS{idVendor}=="2a86",\ ATTRS{idProduct}=="8011",\ GROUP:="dialout",\ MODE:="0666"
openocd -c "adapter driver cmsis-dap; cmsis_dap_vid_pid 0x2a86 0x8011" -c "adapter speed 500" -c "transport select swd" -f "target/stm32f1x.cfg" Open On-Chip Debugger 0.12.0-rc2+dev-00012-g4e077fdda (2022-11-12-16:05) Licensed under GNU GPL v2 For bug reports, read http://openocd.org/doc/doxygen/bugs.html adapter speed: 500 kHz swd Info : Listening on port 6666 for tcl connections Info : Listening on port 4444 for telnet connections Info : CMSIS-DAP: SWD supported Info : CMSIS-DAP: FW Version = 2.0.0 Info : CMSIS-DAP: Interface Initialised (SWD) Info : SWCLK/TCK = 1 SWDIO/TMS = 1 TDI = 0 TDO = 0 nTRST = 0 nRESET = 1 Info : CMSIS-DAP: Interface ready Info : clock speed 1000 kHz Info : SWD DPIDR 0x1ba01477 Info : [stm32f1x.cpu] Cortex-M3 r1p1 processor detected Info : [stm32f1x.cpu] target has 6 breakpoints, 4 watchpoints Info : starting gdb server for stm32f1x.cpu on 3333 Info : Listening on port 3333 for gdb connections