Probably better to create a new channel for 2206Q and other shuttle runs using the "new" Caravel design (see the "Updated Caravel" column in the table at https://efabless.com/shuttle-status). There are some differences in the operation of Caravel before and after this design change, and while there is a lot of commonality, there will be sets of issues that are unique to each of the designs.

Hi Tim. Is there a place/page which summarizes the differences? I believe

2204C

used

mpw5c

tag, but it appears that there were further updates before taping out which we would not have seen ourselves in simulation?

@Tim Edwards Could you invite me to this channel when it is created please? Thanks! It would be super helpful.

I have create a new channel #mpw-6plus-silicon to cover the new Caravel design used on ChipIgnite 2204 and later, and on MPW-6 and later. @Kauser Johar: FYI, there was a bit of confusion over the tags right around the switch to the new design. The first open MPW run to use the new design was MPW-6, but I need to check what tag was on the caravel repository at that time.

Thanks @Tim Edwards. My main worry at the moment is that what we verified internally in simulation may not be logically equivalent to what got taped out which is extremely worrying. This happened without us being aware and given the chance to re-run our internal validation on the new tag to be absolutely sure that it continues to work the way we expect.

@Kauser Johar: The main differences are all corrections to things that were broken, plus one change to the interface between the management SoC and the GPIOs that adds some capability but does not take any away. So if you validated on the old caravel version, it should still be correct, functionally.

👍 - that's all I needed to know.