Can not read memory! Disable Read Out Protection and retry

[Rajesh Tripathi]

Posted on April 16, 2017 at 04:55

Hello, I have problem with a custom stm32f437 based board. It was working for few days then suddenly stopped working and can't program it anymore From keil/St-Link setup.

Installed the ST-Link utility (V4.0) and updated firmware on ST-Link. When I try to connect it says

'Can not read memory!

Disable Read Out Protection and retry.'

Not sure how it got into 'Read Out Protection Level 1'  as I had never even used ST-Link Utility.

When I try to switch to ROP level 0 and deselect all sector and apply, it complains

'Could not set Option bytes!

Please reset the target and retry.'

Already reset/retry many time with no improvement!

The board is unusable now. Please help.

#stm32-stlink #stm32f4-read-out-protection #stm32f437

[Tesla DeLorean]

Posted on July 03, 2017 at 19:34

>>and they do not have any other reports of this problem

Given the level of deployment it would hard not to be awash with problems if this were some systemic issue. The parts are going to have some test time, of which current draw, and voltage levels would undoubtedly be part of the test regiment.

Some better sanity checking of data read out of devices might provide more specific/valuable error messages, some of them currently come as a side-effect of receiving invalid data because the core isn't powered (ie scan chain not viable), or there is some communications/connectivity issue.

The 'I have a custom board..' statement almost always prefaces these dysfunctional situations, and there are plenty of things that can go wrong with a design, up and through manufacturing, whether it's someone mistyping a BOM item, or the wrong reel of parts on a pick-n-place machine, etc.

[Denise Andreozzi]

Posted on July 06, 2017 at 20:51

Actually, I am able to measure 1.25V on the external caps.  We had 3 non-functional units and all three exhibited the same symptoms. We sent 2 of those units over to ST for the failure analysis.  Both had the same results, shorted VCAP pins.  I suppose it is possible that this third unit failed for an entirely different reason, but it seems less likely.  

We have e-mailed our technical contact at ST for any potential explanation.  In the meantime, I am working through the 'nitty-gritty' looking for an error.

[Tesla DeLorean]

Posted on July 06, 2017 at 21:50

1.25V wouldn't sustain a short-to-ground analysis.

[martin su]

Posted on August 23, 2017 at 17:30

Hi Denise,

Have you found the root cause of this issue? I encountered one similart issue with STM32L072 chip,could you share some update  about this issue? thanks.

[Reema O]

Posted on October 30, 2017 at 19:13

I am also facing the similar issue with STM32F405. Any updates? Do we need to update ST-Utility software?

[Tesla DeLorean]

Posted on October 30, 2017 at 20:54

In my experience software updates will not fix board level shorts or incorrect components or design. 

What voltage do you measure on the VCAP pins?

Has the designed be reviewed by an ST FAE?

[Reema O]

Posted on October 30, 2017 at 21:26

VAP_1 1.85 and Vcap2 is 1.18 

How can I contact ST FAE

[Tesla DeLorean]

Posted on October 30, 2017 at 21:28

They should both be around 1.25V, check part orientation.

Via the sales manager for your account, or via the local sales office.

[Reema O]

Posted on October 30, 2017 at 23:24

Do you know if VSO bit of PWR_CR if not set properly can cause this problem?

[Tesla DeLorean]

Posted on October 31, 2017 at 00:12

The VOS comes into play when running at higher speeds, I'd expect the part to be running at 16 MHz off the HSI during the SWD/JTAG programming and interaction.

Check and set the options to Level 0

The other effective signs-of-lift test is to pull BOOT0 High and send the 0x7F data pattern to USART1 (9600 8E1) or USART3 and check for 0x79 response. If the System Loader is non-responsive assume the chip is non-functional as placed on your board.

Make sure VDDA is powered, check the level on NRST