51822 SDK 12.3 DFU setting

[June6]

Hi Sir,

In this project, we design with nRF51822-QFAA (Flash: 256KB, RAM: 16KB) and developed the application and bootloader through the nRF51-DK (pca10028).The file path is nRF5_SDK_12.3.0_d7731ad\examples\dfu\bootloader_secure\pca10028_debug\arm5_no_packs

We hope to test and upgrade the application through the DFU in nrf51-dk board.

Due to the RAM size is difference with nRF51822-QFAC. We need to change the default values in the program.

The default Settings are as follows.

  IROM1 Start: 0x36000  Size: 0x9C00                 IRAM1 Start: 0x20002C00  Size: 0x5380

After using the above IROM and IRAM Settings and upgrading the boot loader file to nrf51822-qfaa (program with nRFGo studio or nrfjprog), the boot loader cannot work and I cannot see the device name "DFUTarg".(program SD + boot loader)

But nRF51822 - QFAC can

Thank you.
June6

[Sigurd]

 Hi,

For the nRF51822-QFAA variant, try to use  IRAM1 Start: 0x20002C00 Size: 0x1380 instead.

[June6]

I've tried this before, and there are new problems

Looks like there's no space for anything

[June6]

Hi，Sigurd

Do you have a solution?

[Sigurd]

Yes, try IRAM1 Start: 0x20002600 Size: 0x1A00 instead.

[June6]

All right, everything's working fine. But how did you get that. And what do I do when I change it to QFAB or change to other chips like 52832

[June6]

Can you tell me, plz.

Wish you all the best.

[Sigurd]

When enabling the SoftDevice, the function sd_ble_enable() in softdevice_handler.c will tell you how much RAM the SoftDevice needs. When setting IRAM1 start to 0x20002600, 0x2600 will be allocated to the SoftDevice, and rest to the application(0x1A00). In total you have 0x2600 + 0x1A00 = 0x4000 = 16 kB. We have a guide here you should read, it's 3 years old, but it covers the basics.