RE: Not able to switch code from NRF51822 QFAC chip to NRF51822 QFAA chip

tesc — Wed, 30 May 2018 13:34:30 GMT

Hi,

The size of the program itself should not matter, as the available flash is the same, but the amount of RAM might be a problem.

The RAM requirement of the SoftDevice depends on configuration, see the documentation for sd_ble_enable() for how to obtain the minimum RAM requirement for your configuration.

Then you must make sure to configure RAM usage correctly. If you use Keil, you do that in "Options for Target", the "Target" panel, under "Read/Write Memory Areas", where IRAM1 Start and Size are the start address and size of application RAM area. It should start at 0x20000000 plus the RAM requirement of the SoftDevice (e.g. 0x200033B0 for a randomly chosen SDK example applicaiton). Its size should be such that Start + Size equals 0x20004000 for the QFAA (16 kB of RAM) or equals 0x20008000 for the QFAC.

Depending on your configuration, the RAM requirements of your application, and the combined stack usage of the SoftDevice and your application, the QFAA might or might not have enough RAM. In that case you can either try to reduce RAM usage by changing SoftDevice configuration, change optimization level for your application, optimize your application manually. Or, increase available RAM by continue using the QFAC.

Regards,
Terje