About nRF5340 programming problem

[Gary.Yang]

Hi Sir,

We are a third party programmer manufacturer.

We are currently developing the nRF5340 programming software.

Encountered the following problems, please help to confirm.

The test programming process can be correctly programmed and verified,

But after the power on is reset, the data in the flash memory all become 0xFF, and the J-link tested also has the same problem.

The attachment is our hardware circuit, is there anything that needs to be modified or suggested?

[Jared]

Hi there,

A power-on-reset will not erase the board, so I'm guessing that you are somehow sending an erase command during the debug process. 

The attachment is our hardware circuit, is there anything that needs to be modified or suggested?

Assuming that it's the nRF5340 QKAA:

1. No series resistor is necessary on the SWD lines
2.  Decoupling capacitor on reset is not needed
3. No 0hm resistor between XC1 and XC2
4. You need an extra decoupling capacitor on DECRF/DCR node
5. It would be nice if you could specify the size of the decoupling capacitors

Are you using nRF Command Line Tools ( nrfjprog) to program the board?

regards

Jared