Would like to know how to keep the QN908x firmware secure from any unauthorized person updating. Is there any lock system to protect the firmware loading, let me know if there is any document explaining these.
I don't thing we can really restrict programming pin access so would like to know is there any code logic (like Cryptographic keys).
I apologize for the delay in my response.
The QN908x contains "Code Read Protection" (CRP) support. This is a mechanism that allows the enabling of different security levels in the system to protect their software and hardware. A specific location in flash memory stores the settings of this mechanism. When the MCU boots, this specific location in flash memory is read, and depending on its value, the MCU may prevent access to the flash memory by external devices.
The table below describes which actions are blocked at each CRP level.
Chapter 7. Boot Process from the QN908x user manual has more detailed information.
For more information about the CRP security levels, could you please read Using Code Read Protection in LPC1100 and LPC1300? This application note was released for another MCU, but it has a very detailed description of how these mechanisms protect your system, and it also applies to the CRP in the QN908x.
Please tell me if you need any more information.
Great to hear that you found it helpful.
Please let me know if you have any further questions about our documentation, or if you need any other information.