Error: Flash Download failed - "Cortex-M0" ----- with Fujitsu MBH7BLZ02-109004

[nsteffensen]

I have two boards based on nRF51822 parts:

• Nordic dev kit PCA10005 Rev 2.2.0 2014.14, chip marked N51822-QFAAG0-1351AG
• Custom board with Fujitsu MBH7BLZ02-109004 module, RF shield obscures chip marking

Trying to run the "blinky" sample code using Keil (MDK-Lite Version 5.12.0.0) with a Segger J-Link LITE CortexM emulator.

• Emulator sees the nRF51822 on both boards. I can tell because the voltage (VTarget) is slightly different on each.
• The Keil Flash > Erase command executes successfully on both boards
• "Blinky" loads (flash programs) and runs on Nordic dev kit
• "Blinky" load FAILS on custom board with the Fujitsu MBH7BLZ02-109004 (error pasted below)

All I do is unplug the emulator from one board and plug it into the other, no settings changed in the project. This is consistent whether I rebuild or not, or target -AA -AB or -AC devices. I lowered JTAG speed from 2MHz to 100kHz with no change.

Its possible the custom board might have a problem, but since voltage is good (3.3V) and the SW port works (sees target, can erase flash) I can't figure out what that might be to affect internal flash programming. JTAG speed makes no change and problem is very repeatable, so it doesn't feel like signal integrity.

This is my first time with Keil and ARM in general, which is why I am starting with "Blinky", so I am hoping it is just a newbie issue but don't know where to start. I read posts with same error code but they seem to be Keil setup issues (not my case since the dev kit works), or memory map settings (not my case I THINK because I make no settings changes).

Any suggestions what might make Keil see an nRF51822, be able to erase its flash using Flash > Erase, but not be able to erase its flash during a load? (yet work on a different model board)

Many thanks...

Error:

Target info:

Device: nRF51822_xxAA VTarget = 3.313V State of Pins: TCK: 0, TDI: 0, TDO: 1, TMS: 1, TRES: 1, TRST: 1 Hardware-Breakpoints: 4 Software-Breakpoints: 8192 Watchpoints: 2 JTAG speed: 100 kHz

Erase Failed! Error: Flash Download failed - "Cortex-M0"

[Håkon Alseth]

Could you try to use nrfjprog to erase the device and then program it with the blinky example? You can call this from the command line: nrfjprog --eraseall

[nsteffensen]

That did it, can't thank you enough! Can you tell me why this needed to be done?

[Håkon Alseth]

No problem:) The chip had the softdevice present in flash, and the flashing algorithm in Keil will give you an error if you try to overwrite it's area (only if SD is present ofcourse). Have a good weekend! Cheers,Håkon

[nsteffensen]

So for posterity:

• The Fujitsu MBH7BLZ02-109004 module apparently comes from the factory programmed with a soft device.
• With a soft device installed, some of flash is hardware protected so attempts to write to it will fail.
• The Keil [Flash > Erase] command does not erase soft devices, and does not indicate failure to do so.
• Using the DOS command line utility "nrfjprog --eraseall" DOES erase soft devices. It is located by default in "C:\Program Files\Nordic Semiconductor\nrf51\bin"
• Nordic dev support rocks.