Chip Lock doesn't make a difference for PSoC3?

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JoBr_1593366
Level 5
Level 5
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I burned a firmware with PSoC Programmer, with and without Chip Lock enabled, and in both cases it says

Programming Succeeded

Doing Checksum

Doing Protect

Programming of Flash Succeeded

and in both cases when I try to read from it, it says

--- User's Flash Area ---

0000: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

0010: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

0020: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

0030: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

0040: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

0050: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

0060: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx

for all rows.  So there's no difference?

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1 Solution

Hi,

Yes you are correct.

If you enable the WOL then only the chip is permanent and cannot be erased.

You can enable the WOL by following certain steps given the below document - https://www.cypress.com/file/137441/download

pastedImage_1.png

Regards

Alakananda

Alakananda

View solution in original post

5 Replies
Alakananda_BG
Moderator
Moderator
Moderator
50 likes received 250 sign-ins 250 replies posted

Hi,

Can you let us know if you have enabled protection in the your program in PSoC Creator?

You can refer to the below table for more information

pastedImage_0.png

Regards

Alakananda

Alakananda
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I don't see a below table, but yes, Device Protection is enabled in the System page of both bootloader and application.  Debug Select is set to SWD instead of GPIO, though. 

But I thought that Device Protection was only written to the chip while Chip Lock was enabled in PSoC Programmer?  It seems to be enabled regardless, which would be good for us because our factory hadn't enabled Chip Lock while burning previous products.  I just want to understand if that's correct or not.  I know on PSoC4 it behaves differently whether Chip Lock is enabled or not, but on PSoC3 it appears to make no difference.

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Alakananda_BG
Moderator
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50 likes received 250 sign-ins 250 replies posted

Hi,

In PSoC 3/5 if we enable the flash protection to full then you cant read the flash with or without chip lock enabled as per the table.

Whereas in PSoC 4 as per the same table you can read the flash even with flash security setting as full protection with external programmer.

If you want to protect flash in PSoC 4 to read from external programmer you have to enable the protected security mode in systems tab and program the hex file using PSoC Programmer with chip lock enable.

Kindly let us know if there is any confusion.

Regards

Alakananda

Alakananda
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Ok, it looks like that table is from Introduction to Bootloaders https://www.cypress.com/file/45346/download

So on PSoC3, does Chip Lock setting do anything?

2.5.3 

Chip Lock

You can enable or disable programming of Write Once Latch (WOL) for PSoC 3 and PSoC 5 devices. This option is disabled by default

So it only affects WOL?

  • On PSoC3
    • Full Protection with Chip Lock disabled will block External read and write, and Internal write, but chip can still be erased and overwritten.
    • Full Protection with Chip Lock enabled will block External read and write, and Internal write, and chip is permanent and cannot be erased
  • On PSoC4
    • Full Protection with Chip Lock disabled will block External write, Internal write, but not External read
    • Full Protection with Chip Lock disabled will block External write, Internal write, and External read

Is that correct?

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Hi,

Yes you are correct.

If you enable the WOL then only the chip is permanent and cannot be erased.

You can enable the WOL by following certain steps given the below document - https://www.cypress.com/file/137441/download

pastedImage_1.png

Regards

Alakananda

Alakananda