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Chip Protection | Cypress Semiconductor

Chip Protection

Summary: 10 Replies, Latest post by vsrs on 07 Nov 2016 07:31 AM PST
Verified Answers: 1
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Graeme Parker's picture
User
43 posts

Hi

I have a design which is just about to be released into the wild.

Obviously I'd like the design to be protected and not readable. In the system tab of the .cydwr there is a selection for chip protection. It defaults to open but I believe I need protected - to stop others from reading/copying the device.

So I set this field to protected and programmed the PSoC4. But, I am still able to action a debug-without-reprogramming and attach-to-running-target. The debugger then allows me to read the memory. What am I doing wrong?

Ta.

user_1377889's picture
User
9606 posts

Set the Debug Select to GPIO, so debugging gets disabled.

 

Bob

Graeme Parker's picture
User
43 posts

I was thinking about doing that. Is that the official way to stop being able to read the "protected" device?

user_1377889's picture
User
9606 posts

Yes, debugging must be disabled. As a side-effect the power consumption decreases a bit.

 

Bob

Graeme Parker's picture
User
43 posts

Well your suggestion certainly works.

I did find this: http://www.cypress.com/knowledge-base-article/flash-read-protection-boot...

Which suggests that using Creator to program the device will NOT put the chip into a protected state. You have to use the PSoC Programmer application.

user_1377889's picture
User
9606 posts

Last option is to set protection to "Kill" which is irrecoverable. No erase, no debug. Devices may not be returned to Cypress for failure analyzes.

 

Bob

user_1377889's picture
User
9606 posts

Are you using a Bootloader?

 

Bob

Graeme Parker's picture
User
43 posts

Yes.

user_1377889's picture
User
9606 posts

So I would suggest to keep away from the "Kill" protection, I don't know whether bootloading works with that setting.

 

Bob

Graeme Parker's picture
User
43 posts

Kill seems v.severe. I don't think I want to go there.

vsrs's picture
Cypress Employee
24 posts

Hi Graeme,

In order to enable chip protection(avoid flash reading over SWD interface) and still have bootloadable option please follow the steps described

1.Set the Chip Protection to Protected in the .cydwr of both the Bootloader and Bootloadable projects. 

2. Now Open PSoC Programmer --> Enable Chip Lock Feature (Options -> Chip Lock -> Enable) and program the Bootloader hex file from PSoC Programmer.

3. Now disconnect the programmer and bootload the cyacd image from the Bootloder Host.

4. Try to Read Flash from PSoC Programmer -> You can see the message: “Chip is in Protected Mode. Any access to Flash is Suppressed". 

5. You can still bootload new images after entering into the bootloader mode but flash reads would be prevented (You can do a Hardware Reset to enter Bootloader mode and perform a new bootload). 

6. Note that if you now try to program another project from Creator, it does not allow doing the same.

7. If you would like to program another project into the device, then please "Disable Chip Lock Feature" and program the new project from PSoC Programmer itself for the first time. Afterwards, you can use Creator itself to program

Best Regards,
VSRS

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