https://devzone.nordicsemi.com/f/nordic-q-a/8333/how-can-i-create-an-nrf51422-bootloader-for-s120-and-s210Can the chip be updated from an ANT device to a BT Smart Central. This means it starts its life with an S210 and then gets a serial code update to an S120. Obviously with different application code as well. I&#39;m not sure if it will need to go the otheren-USTelligent Community 13Thu, 23 Jul 2015 11:52:02 GMThttps://devzone.nordicsemi.com/thread/30166?ContentTypeID=1Thu, 23 Jul 2015 11:52:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0bc69ece-a941-4947-b5cf-22f78fe2e9a9Hung Bui<p>Hi Gary,</p> <p>I think it&#39;s fine.</p> <p>You can switch between different softdevice, as long as they have compatible MBR. Currently we only have 2 MBR variant, v1.0.0 and v1.0.1 and they are compatible.</p> <p>What you have to do is to update both softdevice and bootloader. So you don&#39;t have to worry about incompatible between new softdevice and old bootloader. Our current bootloader support this feature to update them at the same time.</p> <p>Regarding your question on Region0 and Region1, we use MBR to overwrite the softdevice and the MBR is located in Region 0, so it&#39;s not a problem. Note that you should not set region 0 by setting &quot;Enable Softdevice protection&quot;. This will limit the size of the softdevice, that you can extend it by update to a bigger size softdevice.</p> <p>The size of the bootloader now not defined by size of region0 (CLENR0) but provided by a register in flash (@ address 0x3000) in the softdevice, the MBR or the application can read this address to find the size of the softdevice.</p><div style="clear:both;"></div>