nRF52 Flash memory vs EEPROM

RE: nRF52 Flash memory vs EEPROM

Chris Ergo — Sun, 03 Jun 2018 14:58:52 GMT

Another option is the on-chip UICR, which I believe reduces or eliminates your Flash cons 3, 4, and 5, but it only holds 32 32-bit words. Another Flash (and UICR) con that you didn't list is you have to erase a whole or half block at a time. (In the case of UICR, you have to erase all of it to modify any value more than twice(?).) This makes them clumsy for storing user settings that can change often.

RE: nRF52 Flash memory vs EEPROM

Jeong Hyun Seok — Tue, 07 Mar 2017 01:21:08 GMT

Thank you. :-) It helps me a lot. I might goes to TWI(=I2C) eeprom - slow but fewer port and power consumption

RE: nRF52 Flash memory vs EEPROM

endnode — Mon, 06 Mar 2017 10:32:32 GMT

You got it right I believe, not much to add. Internal flash in nRF5x chips is pretty slow (erasing), it is blocking MCU (so if Soft Device runs some heavy BLE operation - such as connection with low connection interval - it can be postponing erase which can cause troubles, you also need to go through SoftDevice API for flash access if you want to do some operation while SD is enabled) and it has pretty large pages (1kB on nRF51 and 4kB on nRF52) which makes some standard use cases problematic (e.g. some filesystem with low overhead/file size). So the question you should ask yourself is: "What NVM storage use cases you need to support on your product?" and this will give you very good hint if you need to invest into external memory chip (whatever flash or EEPROM) or not. It costs you BOM, PCB real estate, one bus (typically SPI) on nRF5x chip + FW integration (driver).