How the S110 works? Before enter the main function, what happens?

[Bee]

I meet a trouble like this:

My colleague used "nRF51822 QFAAC0 1322AW" to make a product. The KEIL program "based on s110_nrf51822_5.2.1_softdevice.hex and nRF51 SDK V4.3.0.27417" he gave me is OK, and the product works well.

Now I need to update the design, and used the "nRF51822 QFAAG3 1440BE", I try to transplant his program to a new one "based on s110_nrf51822_6.2.1_softdevice.hex and nRF51 SDK V6.1.0.b2ec2e6". However, it dosen't work. When I try to debug, the program won't goes into the main funtion.

I'm sure the circuit is OK because the old program works with the old s110_nrf51822_5.2.1_softdevice.hex. There is a system-off circuit to auto-controll if the nRF51822 SLEEP or not.

So I want to ask, what happens before the main function? Why I can't goes into the main function? Is it possible that as soon as I download the program, the nRF51822 sleeps without goes into main function?

[Annim]

well, it can be any reason for this error or problem to occur, in your new design, whether clocks are provided correctly or not?(16MHz and 32kHz). Next would be sdk the version you jumped from v4 to v6, will that compiled perfectly? Nextly, what version of chipset the previous one was and what is of the current one? Check out here for the chipset and sdk compatibility stuff. How this piece of pdf might help you out. Or try porting your code to newer one which will build on top of sdk v6 for s110. That may kick out issues. And before main function , there some house keeping initial settings are performed to set the stack pointer or ram settings which is arm related stuff, not nordic specific task.Good Luck.

[Bee]

Thank you, I have resolve the problem. I used a V7.0.HEX and set the size 88KB, then all is well.