why am I getting a communication failure when trying to connect with stlink-v2 using openocd

Question

I'm trying to connect to an 'stm32' 'bluepill' using an stlink-v2 to write some code to it

Whenever I run openocd, it fails to connect My openocd.cfg file looks like this

source [find interface/stlink-v2.cfg]
source [find target/stm32f3x.cfg]

when i run openocd, this is the response i recieve:

Open On-Chip Debugger 0.10.0
Licensed under GNU GPL v2
For bug reports, read
    http://openocd.org/doc/doxygen/bugs.html
adapter speed: 1000 kHz
adapter_nsrst_delay: 100
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
none separate
srst_only separate srst_nogate srst_open_drain connect_deassert_srst
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : Unable to match requested speed 1000 kHz, using 950 kHz
Info : clock speed 950 kHz
Info : STLINK v2 JTAG v35 API v2 SWIM v7 VID 0x0483 PID 0x3748
Info : using stlink api v2
Info : Target voltage: 3.166623
Error: jtag status contains invalid mode value - communication failure
Polling target stm32f3x.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 100ms
Info : Previous state query failed, trying to reconnect
Error: jtag status contains invalid mode value - communication failure
Polling target stm32f3x.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 300ms
Info : Previous state query failed, trying to reconnect
Error: jtag status contains invalid mode value - communication failure
Polling target stm32f3x.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 700ms
Info : Previous state query failed, trying to reconnect
Error: jtag status contains invalid mode value - communication failure
Polling target stm32f3x.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 1500ms
Info : Previous state query failed, trying to reconnect
Error: jtag status contains invalid mode value - communication failure
Polling target stm32f3x.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 3100ms
Info : Previous state query failed, trying to reconnect
Error: jtag status contains invalid mode value - communication failure
Polling target stm32f3x.cpu failed, trying to reexamine
Examination failed, GDB will be halted. Polling again in 6300ms
^C

I had previoulsy written some code to the stm32f103 on the bluepill and when i connect to my PC,the code runs(it causes the led on pc13 to blink)

I haven't altered the openocd.cfg file sice the last time it worked well

Answer 1

Press and hold the reset button while OpenOCD is trying to connect.

I was getting the exact same error on my STM32F3DISCOVERY board.
Doing this allowed me to connect again.