nrf51 DK using Keil: Error: Flash Download failed - "Cortex-M0"

[brianreinhold]

It is amazing how common this error is - there must be 100 posts. Yet none solve the problem and none explain it. It suggests that there is some serious work needed to improve the error message. This error message is almost as bad as saying Error: Flash Download failed.

I have tried two SDKs with my new nrf51 DK for nrf51822: SDK 10.0.0 and SDK 8.1.0 Both give the same result

I get as far as being able to build the project (BTLE peripheral health thermometer), flash the SoftDevice, and then when I try to flash the actual hts HEX file I get

Erase Failed

Error: Flash Download failed - "Cortex-M0"

Now there are many perturbations one starts to try to solve this ubiquitous bug.

• Turn off erasing in the flash config. Well, big deal. Now I get just the Error: Flash Download failed - "Cortex-M0" message.
• Found one needed to migrate to new project formats with 8.1.0 - cost 6 hrs but in the end, same result.
• Try changing the address bounds (which are the same for the SoftDevice flash and the hts flash). No difference (seems to be ignored)
• Use nrfConnect to erase the entire chip and install the SoftDevice - no change
• I tried to use nrfConnect to install the hts HEX on top of SoftDevice but could never figure out how to set it up in the file memory window
• I've seen comments about incompatible SoftDevice and SDKs so I have tried a couple of SDK versions - none worked so far (at least when using s110 - I think I got one to work using s120 in SDK 10.0.0 but I need s110)

This stuff should work out of the box. I had no such issues with nrf52. What is going on?

[Susheel Nuguru]

The most common issue with this error when using softdevice is, flashing wrong softdevice version with the application.

Every softdevice version, expects the application to start at a particular start address. If your application is compiled to use the memory address reserved for softdevice, then the flashing would fail.

Which version of softdevice did you flash? did you check the application start address to match the size of the softdevice given in its release notes?

[Susheel Nuguru]

Also as you can see here, the supported softdevice for SDK10.0 are 

    - S110 v8.0.0
    - S120 v2.1.0
    - S130 v1.0.0
    - S210 v5.0.0
    - S310 v3.0.0

check their release notes to see if the softdevice you use is same as one of these and the application start address is same as suggested in the release notes of the softdevice.

[brianreinhold]

I have given up on SDK 10.,0,0 foir the time being. I would have assumed that the SoftDevice provided with the SDK would be compatible with the SDK. Pretty bad if they were not!!