ARM SWO ITM Console Bidirectional Standard I/O Retargeting

The ARM Cortex M architecture has many features which are underused, probably simply because engineers are not aware of it. SWO (Single Wire Output) is a single trace pin of the ARM Cortex-M CoreSight debug block. trace pin uses the ITM (Instruction Trace Macrocell) on ARM Cortex. It provides a serial output channel, at a high speed higher than the usual UART, because it is clocked at half or a quarter of the core clock frequency, depending on the core and implementation.

As such, it is an ideal high speed output channel to send text or data to the host. This is how it is usually used, but what is unknown to many: it can be used in a bidirectional way with the help of the debugger.

The topic of this article: how to redirect standard I/O like printf() or scanf() using the SWO ITM console: means both sending *and* receiving data over the SWO debug channel: that way I can use it as a kind of UART with a single pin only.

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NXP MCUXpresso IDE 11.7.0

It is the exam and grading time at the university, and the same time I’m preparing the lectures and labs for the new semester starting mid of February. I’m always heading for using the latest and greatest tools in my labs. A few days ago, NXP released the new version of the MCUXpresso IDE, version 11.7.0. Time to check it out…

NXP MCUXpresso IDE 11.7.0
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McuOnEclipse Components: 29-Dec-2022 Release

I’m pleased to announce a new release of the McuOnEclipse Processor Expert components, available on SourceForge.

SourceForge

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Fixing “REENT malloc succeeded” Assertion

One little nasty assertion in the GNU standard library appeared a few days ago, kind out of nowhere, reporting “REENT malloc succeeded”:

Obviously it was caused by the call to srand() which sets the ‘seed’ for the standard library (pseudo) random number generator. The assertion happens as well later for calling the rand() function.

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Picoprobe: Using the Raspberry Pi Pico as Debug Probe

In Getting Started: Raspberry Pi Pico RP2040 with Eclipse and J-Link I used a SEGGER J-Link EDU for debugging: unfortunately, probably because of silicon shortage, these EDU probes are out of stock everywhere. Luckily, there is a solution: just use another Raspberry Pi Pico!

SWD Debugging with PicoProbe

This turns a $5 Raspberry Pi Pico board in to a very usable and versatile debug probe.

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MCUXpresso IDE 11.6.0

With a steady release train, NXP has released last week a new and updated version of their flagship IDE: the version 11.6.0 of the MCUXpresso IDE.

NXP MCUXpresso IDE V11.6.0

And there are several new and cool features with that release, including a power & energy profiler and CMake support.

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MCUXpresso IDE 11.5.0

I’m now in the middle of the university fall semester exam season with writing exams and grading student work, and the same time the new semester courses need to be prepared. With the global silicon and board shortage, this will be again a challenge to equip all the labs with the needed infrastructure. The good thing is that there is no shortage on software and tools side of the infrastructure: NXP released last week their new flagship Eclipse based IDE: the MCUXpresso IDE 11.5.0. Time to check it out for the upcoming lectures and classes….

NXP MCUXpresso IDE Version 11.5.0

Spoiler Alert: It has a new view for FreeRTOS lovers, plus new features for energy/power measurements!

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DIY Split-Flap Display

Split-flap displays are electromechanical display devices, which were common in airports or railway stations a few years ago.Unfortunately, most of them are gone and replaced by LED displays. Why not create a DIY version of it?

2×10 Split-Flap Display
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McuOnEclipse Components: 26-Dec-2021 Release

I’m pleased to announce a new release of the McuOnEclipse components, available on SourceForge. This release includes several bug fixes, support for more devices, and updated components like FreeRTOS, MinINI, Percepio Tracealyzer and SEGGER SystemView.

SourceForge

SourceForge

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