The OpenSDA on the FRDM-KL25Z board is a cool feature: I do not need any external debugging device to program and debug my board :-). But my KL25Z custom board will not have that OpenSDA on it: first because it would add additional costs, and I do not see a way how I could use it for my board. I better start using a SWD/JTAG debugger for my Freedom board to have everything in place.
What I need to add to the black Freedom board is the SWD header:
SWD J6 (populated) and J11 (unpopulated)
There are several reports in the Freescale forums around having ‘secured’ the Freedom board. But what does ‘securing’ a board mean? And what does it mean if I get that ‘Device is Secure’ dialog?
Device is Secure. Erase to unsecure?
There are different levels of protection you can find in many embedded microprocessors, and the terms might vary from vendor to vendor:
Whenever I do a debug launch in the Eclipse based CodeWarrior, it takes some time until actually I’m ready to step through my code on the target. Yes, a good part of that is by Eclipse. But another part is that Eclipse helps me to do stupid things (which is a good thing). But say if I know what I’m doing, I could remove some of that safety belts and still doing fine. But only if I know what I’m doing.
A good indicator where Eclipse is spending time is to have a look in the Progress View:
Progress information during launch
It shows an interesting information: ‘Build before Launch’….
Usually I debug and step on C and C++ level: means I step on C/C++ source lines. But sometimes a finer stepping detail is required. What I need is stepping on assembly level. For first time users of Eclipse, that might not be that obvious, so here is the hint:
In the Debug view toolbar (while debugging), there are the normal stepping commands like ‘step’, ‘step over’ or ‘step out’. All these stepping can be performed on assembly instruction level if I enable the ‘Instruction Stepping Mode’:
Instruction Stepping Mode: Assembly level stepping
In ‘Device is Secure‘ I had a case where this was a false alarm. But recently there has been a report in the Freescale Forum that this can be a real problem with the Freedom KL25Z board I’m using too. I was not able to reproduce this on my end, so a reader of this blog who sent me a binary file to reproduce it.
Well, I was really scared to try that ‘killer’ file on my board, but well, that board is not that expensive, and I have 5 pieces of silicon at hand from a sample order :-). So I took some risk, and programmed that binary using the simple flash programmer. And indeed, when I wanted to debug it again, I got that dialog with my black Freedom board:
Device is Secure. Erase to unsecure?
Usually I compile my sources, link it and pass it to the debugger for downloading it to the target. And ‘downloading’ means for me: flashing to the target (RAM debugging is something for the non-hardcore programmers ;-)). But there are more options than only downloading and flashing. There is definitely more which helps me to do post-mortem (yes, I *love* Latin :cool:) debugging.
Downloading means to me that the debugger will program my application into the device, then loads the symbolics (debug information, source file information, …) and then I debug my application. Looking at the ‘Debug As’ options, there is as well Attach and Connect:
Debug as Attach, Connect and Download
Eclipse provides in the Editor view great tool tips (called ‘hovers’) which shows what is behind a macro: I can move my mouse over it, and it shows me the content behind it:
Macro Expansion Hover in Editor View
There are always hidden treasures in Eclipse, and here is one: By default, variables might look like which is not always what I want:
Variables View
How to change the format to hexadecimal (or any other format)?
P&E has released information and firmware instructions for using the OpenSDA, see pemicro.com/opensda. Future has posted a very useful article about using OpenSDA here. So time to upgrade OpenSDA bootloader and firmware v10.1. My FRDM-KL25Z board is a pre-production board, and I assume the production boards expected next week will have the new firmware on it. But it is always useful to know how to change/upgrade the firmware, as I expect there will be new versions of it in the future.
The schematics for the Freedom board is now available on the element14 Freedom Board site (you need to log into the element14 community first) as FRDM-KL25Z Schematics (SPF-27556_D).pdf (314.7 K)). So time to write a tutorial how to use the LED on that board.
❗ Note: since this tutorial, the LED component has been simplified. So some of the steps below are much simpler and easer. Please see LED’s for Kinetis, simplified | MCU on Eclipse. I have updated this post with the new instructions and images.
In “FreeRTOS with GCC, Cortex-M0+ and Kinetis KL25Z Freedom Board” and “A Shell for the KL25Z Freedom Board” I have used that board with an RTOS: FreeRTOS. But it is really easy to use that board without an RTOS (‘bare metal’) too. In this tutorial I’m providing step by step instructions to use the RGB LED on the Freedom KL25Z board with Processor Expert and the open source LED component.
MCU on Eclipse 