nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

RE: nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

ketiljo — Mon, 18 May 2020 12:42:39 GMT

The serial connection is unlikely to cause this. The schematic looks ok as well.

The nRF9E5 bootloader will load the EEPROM content into RAM and start executing the code when it's done. Then the EEPROM isn't touched until the next power up. Any read write operations of the EEPROM has the handled as a SPI device. So maybe there's something the the code that causes this?

RE: nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

Rima — Fri, 15 May 2020 13:27:20 GMT

Yes, I think we have proper pull ups/downs. We used the same design in other boards with no issue. The one difference with our other designs is the serial connection with another processor(P01, P02). I don't know how that can cause this issue.

RE: nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

ketiljo — Fri, 15 May 2020 11:32:52 GMT

Do you have pull down and pull up resistors on the lines to make sure you always have a defined logic levels? Typically pull up on CS and HOLD. Make sure WP is not floating.

RE: nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

Rima — Thu, 14 May 2020 15:17:18 GMT

Yes, we use SPI interface to write and read couple of bytes at the end of EEPROM. The write is done in specific condition and not normal operation and read is always done at board power up.

RE: nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

ketiljo — Thu, 14 May 2020 10:08:07 GMT

If the nRF9E5 don't have access to the PROG pin of the EEPROM, it's not likely that the nRF9E5 can alter the content of the EEPROM. Do you have control of the logic level of the PROG pin?

RE: nRF9E5 design with 25AA320- EEPROM loses data in rare circumstances

Rima — Wed, 13 May 2020 13:31:25 GMT

[quote userid="90293" url="~/f/nordic-q-a/61329/nrf9e5-design-with-25aa320--eeprom-loses-data-in-rare-circumstances"]it is happening if the board is resting more often[/quote]

resetting more often!