RTT multiple channels

rigomate · Sep 5th 2014, 4:09pm

Hi!

I just stumbled upon Segger's RTT implementation.
I am really impressed with it.

There is only 1 question:
It mentions that there is an opportunity to have multiple channels, aka. multiple up/down buffers.
But the J-link RTT Client does not seem to read from it.

What is the intention of having multiple buffers then?

SEGGER_RTT.c says:

Source Code

RTT channel 0 is always present and reserved for Terminal usage Name is fixed to "Terminal"

So I reckon there is some API to address the debugger hardware to read out the other buffers as well?

Thanks!

SEGGER - Alex · Sep 5th 2014, 4:15pm

Hi,

Thanks for "the flowers".

So I reckon there is some API to address the debugger hardware to read out the other buffers as well?

Yes, there is. Can be accessed via the J-Link SDK.
The RTT Client does not read other channels than 0 because it is undefined in what format data comes over there... this would probably result in garbage being shown...
The RTT client is *an example* for using RTT for printf. As said, it is just an example for what RTT can be used.

We are currently working on a utility called RTT-Logger which will capture data on channel 1 and just store it to a file (just in binary form as it comes from the target, so a third party application can evaluate this data)
The executable will be part of one of the next J-Link software versions.
The source code will be available for J-Link SDK Users.

- Alex

rigomate · Sep 5th 2014, 4:34pm

Thanks a bunch!

Seems then I will stay with the channel 0 possibility.
But still, very nice to have.

The RTT-Logger sounds very promising as well.
I'll keep myself updated.

Thanks

SEGGER - Alex · Sep 5th 2014, 7:38pm

Hi,

How about subscribing to the J-Link software update and notification list?
You will then get informed automatically, when a new version becomes available (and what new features / fixes come with it)
segger.com/notification/subscribe.php?prodid=7

- Alex

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