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Unlocking flash after security is enabled. | Cypress Semiconductor

Unlocking flash after security is enabled.

Summary: 3 Replies, Latest post by Holger Wech on 21 Apr 2017 02:35 AM PDT
Verified Answers: 0
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Tom
Tom's picture
User
8 posts

Hi,

I need to re-flash devices which have the security activated. How can I erase the flash of an MB9BF321K after I have set the security to active (0x00100000 to 0x0001)? 

Segger J-Link isn't capable of erasing it. The SWD interface seems to be blocked completely by this security feature.

The USBDirect software has the erase functions disabled. From older screenshots it seemed that this function was available before but now has been removed for some reason...

Any ideas?

 

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howe's picture
Cypress Employee
21 posts

A secured device cannot be accessed via JTAG. Otherwise this would be a security hole.

You have to use the Burn-In ROM bootloader features, by using the tools USB direct programmer or MCU Flash Programmer.

On both, you have to connect first (button download) and then Erase. After Erase you have to perform Erase.

If you do not see enabled the erase button, then you have not connected by using the download buton (download referes to downloading a kernel that is needed)

regards,

Holger

Tom
Tom's picture
User
8 posts

Hi Holger,

thanks for the info. I've figured it out what I was doing wrong. Reseting the device during this process seemed crucial. This while leaving the power on the module and the bootloader activated.

 

Gr.

Tom

howe's picture
Cypress Employee
21 posts

Thanks for the feedback. Happy to read that it works now. #Holger

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