Error: Flash Download failed - "Cortex - M4" while flashing softdevice from Keil uVision 5

[daniel77]

Failed to flash softdevice s132_nrf52_3.0.0_softdevice.hex using Keil uVision 5 on a nRF52 DK board PCA10040 V1.1.0. Error code:

Erase failed!
Error: Flash Download failed - "Cortex - M4"

Flashing the SDK 12.0 example project is successful. I have to manually drag and drop the softdevice from the SDK folder into the JLink USB drive. The program and softdevice runs successfully with this method. But, the Keil uVision will never be able to flash softdevice. Do I have to edit the memory map in "options for target" menu for softdevice download?

Update: I just tested on another board nRF51 DK PCA10028. I don't have problem flashing the softdevice s130_nrf51_2.0.1_softdevice.hex for this board in Keil uVision and I don't need to edit memory map in "options for target" at all. The problem seems to exist only on Keil for nRF52 DK PCA10040.

[Jørgen Holmefjord]

You will get this error if there is a softdevice present on the device already. Can you try to erase the board using eraseall command in nrfjprog or using nRFgo Studio?

[daniel77]

Just a note, I don't need to do that for PCA10028 board. But, I just checked the box for "erase full chip" under Options for target>Debug>JLink Settings>Flash Download. Then, I use flash>erase. It is a new error now.

Full Chip Erase Done.
Programming Failed!
Error: Flash Download failed  -  "Cortex-M4"

[Jørgen Holmefjord]

Checking erase full chip in Keil will not erase the softdevice. You have to use nrfjprog or nRFgo Studio.

[daniel77]

Alright, it needs to erase with nRFgo Studio first every time before flashing using Keil. If I flash the second time on Keil, the error will pop up. This is strange because PCA10028 can flash softdevice multiple times without the need to use nRFgo Studio to erase all. Anyhow, thanks for the answer!

[Jørgen Holmefjord]

You only need to flash the softdevice if you are switching to another version or if you are running an example that does not require a softdevice. You can just flash your new application and the softdevice will still be present on the device. Also, have a look at this blog post, which describes how you can add shortcuts for nrfjprog commands inside Keil.