NRF52832-QFAB Flash Memory size

[Hiren Bhuva]

Hello Community,

My customer has design a custom board using NRF52832-QFAB MCU. They have also written application firmware as per product need.

Now, Customer wants me to fix some issues in the firmware application source code. But, when I try to understand previous Project, I came to know that they are using 512KB of flash memory in the SES project. However, from the datasheet it looks like NRF52832-QFAB is having 256KB flash memory only.

Now, I am not able to understand how, the existing firmware is working though using 512KB flash memory for NRF52832-QFAB MCU.

Also, From the Application and Bootloader Hex file, I can say that it made for 512KB flash memory.

Please let me know, If my understanding is not right or If I am missing something.

Thanks,

Hiren Bhuva

[Einar Thorsrud]

Hi,

I see a few possible reasons for this not having caused a problem:

1. Have you double checked that they are using QFAB on the boards they have been using?
2. Could it be that even though the are using QFAB and the project is for a 512 kB device (QFAA/CIAA), they have adjusted the bootloader start address and size to fit within 256 kB? If so, that would work. (As you write that you have checked the hex file that does not seem to be the case, though).

[Hiren Bhuva]

Hi Einar,

Thanks for reply,

Yes, I have double checked that we are using QFAB on the board.

Also, I can surely say that we have not adjusted the bootloader start addresses and sizes. 

However, I am doubting that the memory after 256KB of flash shows as Reserved in the memory map.

Please let me know whether the reserved memory can be used as flash? If yes, then can the device misbehave?

Thanks,

Hiren Bhuva

[Einar Thorsrud]

Hi Hiren,

"Reserved memory" means memory that is not to be used by the specific project. So if everything after 256 kB is reserved, then non of it is used and it is expected that the firmware will work on a 256 kB device.