SAMD21 Programming with Atmel ICE Fail to Write I am trying to program my Adafruit M0 with the SAMD21G18 chip with Atmel studio and the Atmel ICE programmer. I have pin 1 on the ICE connected to 3.3V on the M0, pin 2 connected to SWDIO, pin 4 to SWDCLK, pin 10 to Reset, and pins 3, 5, and 9 to ground. This was all according to the ARM SWD connection section of the Atmel ICE manual. In Atmel Studio, I can read the device signature, but when I go to program the chip, I get the following error:

Timestamp:      2017-04-20 22:03:32.563
Severity:       ERROR
ComponentId:    20100
StatusCode:     131103
ModuleName:     TCF command: Modules:writeToMemory failed.

Failed to write segment at 0x0 to target for memorytype


I have searched the internet for hours, finding no solution to this problem.
Whats is the fuse setting of NVMCTRL_BOOTPROT?

it should be:

NVMCTRL_BOOTPROT = 0x07

which will set your memory location to 0x00 (no bootloader).

NVMCTRL_BOOTPROT sets the amount of space to allocate for the bootloader in flash memory. Setting this fuse to 0x07 tells the chip you are not allocating space for a bootloader and the programmer will start to write at address 0x00, which is the beginning of flash memory. If you are programming with an Atmel ICE, you are not using a bootloader.