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chriskuku
chriskuku
Senior II
Feb 9, 2026 2:51 PM UTC
Solved

Error: Data read failed - when connecting to STM32F103C8BT6 Blue Pill

Title edited to flag that this relates to a Blue Pill

I'm trying to connect an STM32-STLink-V2 with three wires via SWD (GND, SCLK,SDIO). Was able to run a firmware upgrade, now V2J46S7.
Clicking on Connect gives:

15:35:11 : UR connection mode is defined with the HWrst reset mode
15:35:11 : ST-LINK SN : XXXXXXXXXXXXXXXXXXXXXXXXXX
15:35:11 : ST-LINK FW : V2J46S7
15:35:11 : Board : --
15:35:11 : Voltage : 3.02V
15:35:11 : SWD freq : 4000 KHz
15:35:11 : Connect mode: Normal
15:35:11 : Reset mode : Hardware reset
15:35:11 : Device ID : 0x410
15:35:11 : Revision ID : Rev X
15:35:11 : Debug in Low Power mode is not supported for this device.
15:35:12 : UPLOADING OPTION BYTES DATA ...
15:35:12 : Bank : 0x00
15:35:12 : Address : 0x4002201c
15:35:12 : Size : 8 Bytes
15:35:12 : Bank : 0x01
15:35:12 : Address : 0x1ffff800
15:35:12 : Size : 16 Bytes
15:35:12 : UPLOADING ...
15:35:12 : Size : 1024 Bytes
15:35:12 : Address : 0x8000000
15:35:12 : Read progress:
15:35:13 : Error: Data read failed
15:37:13 : Disconnected from device.

 

What's wrong?

chriskuku
chriskukuBest answer
Senior II
Feb 10, 2026 9:38 AM UTC

It turned out far less complicated: the RDP bit was set. After unticking it using STM32CubeProgrammer, I was able to read the device.

08:58:28 : STM32CubeProgrammer API v2.20.0 | MacOS-64Bits
08:58:34 : UR connection mode is defined with the HWrst reset mode
08:58:35 : UR connection mode is defined with the HWrst reset mode
08:58:35 : ST-LINK SN : 0A031612A218303030303032
08:58:35 : ST-LINK FW : V2J46S7
08:58:35 : Board : --
08:58:35 : Voltage : 2.88V
08:58:35 : SWD freq : 4000 KHz
08:58:35 : Connect mode: Normal
08:58:35 : Reset mode : Hardware reset
08:58:35 : Device ID : 0x410
08:58:35 : Revision ID : Rev X
08:58:35 : Debug in Low Power mode is not supported for this device.
08:58:37 : UPLOADING OPTION BYTES DATA ...
08:58:37 : Bank : 0x00
08:58:37 : Address : 0x4002201c
08:58:37 : Size : 8 Bytes
08:58:37 : Bank : 0x01
08:58:37 : Address : 0x1ffff800
08:58:37 : Size : 16 Bytes
08:58:37 : UPLOADING ...
08:58:37 : Size : 1024 Bytes
08:58:37 : Address : 0x8000000
08:58:37 : Read progress:
08:58:38 : Error: Data read failed
09:01:09 : Option byte command : -ob RDP=0xBB
09:01:09 : qCmd : -ob RDP=0xBB
09:01:09 : PROGRAMMING OPTION BYTES AREA ...
09:01:09 : Bank : 0x01
09:01:09 : Address : 0x1ffff800
09:01:09 : Size : 16 Bytes
09:01:10 : UPLOADING OPTION BYTES DATA ...
09:01:10 : Bank : 0x00
09:01:10 : Address : 0x4002201c
09:01:10 : Size : 8 Bytes
09:01:10 : Bank : 0x01
09:01:10 : Address : 0x1ffff800
09:01:10 : Size : 16 Bytes
09:01:11 : OPTION BYTE PROGRAMMING VERIFICATION:
09:01:11 : Option Bytes successfully programmed
09:01:11 : Time elapsed during option Bytes configuration: 00:00:01.341
09:01:39 : Disconnected from device.
09:01:41 : UR connection mode is defined with the HWrst reset mode
09:01:43 : UR connection mode is defined with the HWrst reset mode
09:01:43 : ST-LINK SN : 0A031612A218303030303032
09:01:43 : ST-LINK FW : V2J46S7
09:01:43 : Board : --
09:01:43 : Voltage : 2.91V
09:01:43 : SWD freq : 4000 KHz
09:01:43 : Connect mode: Normal
09:01:43 : Reset mode : Hardware reset
09:01:43 : Device ID : 0x410
09:01:43 : Revision ID : Rev X
09:01:43 : Debug in Low Power mode is not supported for this device.
09:01:45 : UPLOADING OPTION BYTES DATA ...
09:01:45 : Bank : 0x00
09:01:45 : Address : 0x4002201c
09:01:45 : Size : 8 Bytes
09:01:45 : Bank : 0x01
09:01:45 : Address : 0x1ffff800
09:01:45 : Size : 16 Bytes
09:01:45 : UPLOADING ...
09:01:45 : Size : 1024 Bytes
09:01:45 : Address : 0x8000000
09:01:45 : Read progress:
09:01:46 : Error: Data read failed
09:01:58 : Option byte command : -ob RDP=0xA5
09:01:58 : qCmd : -ob RDP=0xA5
09:01:58 : PROGRAMMING OPTION BYTES AREA ...
09:01:58 : Bank : 0x01
09:01:58 : Address : 0x1ffff800
09:01:58 : Size : 16 Bytes
09:01:58 : UPLOADING OPTION BYTES DATA ...
09:01:58 : Bank : 0x00
09:01:58 : Address : 0x4002201c
09:01:58 : Size : 8 Bytes
09:01:59 : Bank : 0x01
09:01:59 : Address : 0x1ffff800
09:01:59 : Size : 16 Bytes
09:01:59 : OPTION BYTE PROGRAMMING VERIFICATION:
09:01:59 : Option Bytes successfully programmed
09:01:59 : Time elapsed during option Bytes configuration: 00:00:00.838
09:02:25 : Disconnected from device.
09:02:28 : UR connection mode is defined with the HWrst reset mode
09:02:29 : UR connection mode is defined with the HWrst reset mode
09:02:29 : ST-LINK SN : 0A031612A218303030303032
09:02:29 : ST-LINK FW : V2J46S7
09:02:29 : Board : --
09:02:29 : Voltage : 2.94V
09:02:29 : SWD freq : 4000 KHz
09:02:29 : Connect mode: Normal
09:02:29 : Reset mode : Hardware reset
09:02:29 : Device ID : 0x410
09:02:29 : Revision ID : Rev X
09:02:29 : Debug in Low Power mode is not supported for this device.
09:02:30 : UPLOADING OPTION BYTES DATA ...
09:02:30 : Bank : 0x00
09:02:30 : Address : 0x4002201c
09:02:30 : Size : 8 Bytes
09:02:30 : Bank : 0x01
09:02:30 : Address : 0x1ffff800
09:02:30 : Size : 16 Bytes
09:02:30 : UPLOADING ...
09:02:30 : Size : 1024 Bytes
09:02:30 : Address : 0x8000000
09:02:30 : Read progress:
09:02:30 : Data read successfully
09:02:30 : Time elapsed during the read operation is: 00:00:00.310

 

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9 replies

TDK
TDK
Feb 9, 2026 2:55 PM UTC

> What's wrong?

You probably have a counterfeit chip and/or programmer.

Programmer reports a voltage despite no VCC connected, so maybe you're using this?

TDK_1-1770648844414.png

Non-ST tools often don't work will with newer software.

"If you feel a post has answered your question, please click ""Accept as Solution""."
    chriskuku
    chriskukuAuthor
    Senior II
    Feb 9, 2026 3:12 PM UTC

    I'm using this:


    Andrew Neil
    Andrew Neil
    Super User
    Feb 9, 2026 4:41 PM UTC

    @chriskuku Note that you can put the image directly in the post - then we can see it:

    AndrewNeil_0-1770655156993.png

    That's a fake - see this post by @mƎALLEm 

     

    You still haven't said what board you're using

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    Andrew Neil
    Andrew Neil
    Super User
    Feb 9, 2026 3:06 PM UTC

    You need to give more details about your setup - see:

    How to write your question to maximize your chances to find a solution

     

    As @TDK said, the STM32F103C8BT6 is widely cloned, and there are many fake ST-Links out there.

    This was discussed at length recently in this thread 

    And this thread

    And this thread 

     

    See also: How to recognize a genuine ST-LINK/V2 versus a cloned one.

    A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    TDK
    TDK
    Feb 9, 2026 3:34 PM UTC

    That one looks counterfeit as well, unless the markings have changed.

    How to recognize a genuine ST-LINK/V2 versus a clo... - STMicroelectronics Community

    Plus the board is likely counterfeit.

    "If you feel a post has answered your question, please click ""Accept as Solution""."
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