Sigrok-I3C-decoder

An I3C decoder with SDR and HDR-DDR support for sigrok & pulseview

After releasing an I3C analyzer for Saleae logic, I received a lot of request to make an analyzer plugin for Sigrok Pulseview.

So: Here it is for your enjoyment :-)

Capabilities:

• SDR and DDR mode support
• Diversified decoding for Bit 9. Bit 9 of SDR transfers has several meanings as function of context. ACK/NAK signaling, Parity bit, Continuation / Abort signaling.
• Decoding of ENTDAA. ENTDAA has a frame format which does not follow the normal SDR mode, because the read data payload has no bit 9.
• Special bus conditions are decoded:
  • SDR mode: Start, Stop, Restart
  • HDR-DDR mode: HDR restart, HDR exit
  • target reset condition is detected

Update 24 October '25

I added DSView compatibility. That means, you can now also use this Analyzer also with DsLogic Analyzers.

DSView implements a slightly different version compared to the current Sigrok Pulseview, but the change was easy to apply. In general Sigrog Pulseview is a bit more advanced in how it presents analyzed data - you can turn on/off fine grained what it should show and what not.

Installation instructions

Clone this repository or select the download option on the top right. The I3C analyzer itself is located in the folder decoder in the i3c.zip file.

Navigate to your pulseview decoders directory. For a windows installation with default location you can find it under:

C:\Program Files\sigrok\PulseView\share\libsigrokdecode\decoders

Unzip the i3c.zip file in that directory such that you have the following folder/file structure:

.../libsigrokdecode/decoders/i3c/__init__.py
.../libsigrokdecode/decoders/i3c/pd.py

Or here a view of the final files at the right location on a windows installation:

Testing

The folder decoder also contains an example Waveform. This waveform was pragmatically decoded from a saleae logic capture, but the conversion was not perfect. Content wise it is correct, but the timeline is not - dummy samples got inserted. This is no functional problem though - the file decodes correctly.

This .sr file also includes already an i3c decoder in the waveform.

The decoder can also be executed to output textual decoding data using sigrok-cli:

sigrok-cli -i ExampleWaveform.sr -P i3c:scl=D0:sda=D1 -A i3c=address-read:address-write:data-read:data-write

The parameters following -A select which aspects of the decoding you would like to see in the textual decoding.

Execute:

sigrok-cli -P i3c --show

to see which items you can add to -A.

Here a few decoding views:

HDR-SDR decoding

HDR-DDR decoding

HDR-ENTDAA decoding

A unit test to get into official integration into Sigrok is yet to be done.

Other I3C projects for your reference

Looking for an I3C analyzer plugin for Saleae Logic?

Have a look at my I3C daughter project, which is a Saleae Logic Analyzer plugin to decode I3C OD, I3C SDR and I3C HDR-DDR transfers: https://github.com/xyphro/XyphroLabs-I3C-Saleae-Protocol-Analyzer

In need of an I3C Controller which can be controlled from a PC?

Have a look at my I3C daughter project, which is USB to I3C interface based on a cheap Raspberry pi PICO 2040 board. https://github.com/xyphro/I3CBlaster