Broken bit in RAM region

[Vlad Mokhnachov]

Hi, Nordic! We have two PDK-NRF52840 and custom boards with NRF52840 chips. 2 from 5 chips have a broken bit in RAM. This is different places. For example:

Is this problem only for preview chip? Will You make manufactoring tests for serial chips?

Update: 2 from 6.

[Hung Bui]

@Vlad : The preview chips should be tested. It pretty strange that you see the error on 2 out of 5. Where are the 2 defected chip mounted ? It's on our PDK or on your board ?

Could you try to run the chip in debug mode, add a break point and try to change the RAM value at that address? Or create a small code to directly change RAM value at that address ? Just to verify it's not the issue with J-Link Commander.

If you still see the issue, I would suggest you to create a case on our support portal (MyPage), we would need to get hold of the chips for further investigation.

[Vlad Mokhnachov]

Problem with variable in debug mode was a reason for experiments with J-Link Commander. It's happen on your PDK board and on our board. New chip on the same board works good.

[Hung Bui]

Could you please create a support case on our MyPage ? We need more information about the chips and to get the chips here (you will have a replacement). Please provide link to this thread. Also please take a close-up photo of the chips.

[Hung Bui]

Also could you try to test with just "while(1);" in main() ? Seems that the RAM address is inside the stack area?

[Vlad Mokhnachov]

What means this test? I erase all memory(RAM and Flash). After I read all memory bytes.(I made this test not once) First chip have a broken byte at 0x200137EB Second chip have a broken byte at 0x2003D801