How to identifier nRF51 SoC chip?

[wen jin zhang]

I try use the FICR information to identifier nRF51. but found some interesting staff when i read 0x10000000 first 16 bytes by SWD memory read. when I power on read. it return all 0x00. but i restart SWD debuger read again. it will return 0xAA 0x55 0xAA 0x55 0xAA 0x55 0xAA 0x55 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF

and CONFIGID also same.

do FICR be RTL? why could be changed, ? is there has fixed area can be used as identifier?

[Susheel Nuguru]

Not sure why you were reading 0x00's but the FICR is permanent device and calibration data tuned for each chip, it will/should not change.

[Susheel Nuguru]

Hi vjzhang,

I am not sure how you are entering debug mode. I can see your function calls but i cannot see what they are doing. The quote from specs says that you need the below

Debug interface mode is initiated by clocking one clock cycle on SWDCLK with SWDIO=1. Due to delays caused by starting up the DAP's power domain, a minimum of 150 clock cycles must be clocked at a speed of minimum 125 kHz on SWDCLK with SWDIO=1 to guarantee that the DAP is able to capture a minimum of 50 clock cycles.

I do not see where you are doing this.