CERN IPMC and MMC-based AMC cards

1

Hi,

We maintain the IPMC for the ATLAS LAr Phase-I upgrades, and we’ve been asked to investigate switching to the CERN IPMC.

When using the CERN IPMC, the main blade power sequencing works. The next thing we tried was to power up AMC cards plugged in to the main blade. The AMC’s have a standard MMC and are know to work with the LAPP IPMC. The AMC cards initially power up, but after about 10 seconds, the power turns off. We have tried this with 2 completely different AMC modules and see the same behavior for both. Do you have any suggestions?

Regards, John Hobbs

2

Hello John,

this should work, since the interface of the CERN-IPMC was designed to be compatible with the LAPP IPMC. Also TileCal are using the CERN IPMC on their AMC carrier and have not reported any issues.

Can you please share your CERN-IPMC software project (XML configuration file, user code, etc.)?

cheers,

Stefan

3

Hi Stefan,

The repo is https://gitlab.cern.ch/atlas-lar-be-firmware/HL-IPMC and @mlyukova has given you developer access. There are multiple boards targeted in this repo, but the one under discussion is the “LArC” (with various capitalization). The build command for this board is:

 python compile.py -c config_LARC.xml -b BOARD_LARC

and within the c code there are if/else tests for the various board types so just keep an eye out for this.

4

Hello John,

thank you, I can access the repository, although it is not clear to me how the user code C files that re not meant for a given board are excluded from the compilation.

I did however check the AMC part in the XML config file and this looks ok. The only difference to the configuration that we use in our IPMC production test is the inversion of some pins. Did you double-check that this is indeed correct?

Also you said the AMC powers off, I assume you mean the AMC payload power? This could indicate an issue with the payload power good signal.

cheers,

Stefan

5

Hello John,

can you also please send the IPMC debug console output when inserting and AMC?

cheers,

Stefan

6

Hi Stefan,

Thanks. We will send you the output. It may be a little while because we’ll be adding some wires to see the console (the LAPP IPMC had separate connector) and for the control lines to get them all on a scope.

7

Hello John,

thanks, this will be helpful since the SDI output should contain some debug prints when inserting the AMC.

If you have access to the Ethernet interface, you could also try to redirect the SDI UART to SOL by uncommenting the following key in the XML:

https://gitlab.cern.ch/ep-ese-be-xtca/ipmc-project/-/blob/master/config.xml?ref_type=heads#L66

In this case you would not need to solder wires for the UART.

cheers,

Stefan

8

Thanks. I’d forgotten about that option.