[Ftk_hardware] crates

[Mel Shochet]

Thanks Paola.  The biggest concern of the review committee was the 48 
volts, its grounding and noise issues.  If you think that the power may 
be a factor of 2 lower, that makes a big difference.  On our side, I 
looked at the ATCA specs for transition boards.  The depth of the card 
is very small, in all likelihood much too small for all of the 
functionality we need on the AM AUX card.

At the April 5 meeting, Ted will talk about the possible use of ATCA in 
the DF crates.

                        Regards,
                        Mel


On 3/24/2011 2:01 AM, Paola Giannetti wrote:
> I am sorry for the late answer, yesterday I couldn't see e-mails.
>
> I think we cannot use ATCA for the core crates for a lot of reasons 
> that I already explained, even at the review:
> (1) we need early to test the system with the new chip, let's say next 
> year and it is not realistic to have a new AMBoard, new LAMB and new 
> CPU interface for the next year. It is very important to be able to 
> measure currents, capability to work at 100 MHz and with the new chip, 
> before the end of 2012. We will never do it if we change crate
>
> (2) We are ahead designing the LAMB, the AMBoard and the AMchip. The 
> suggestions of the reviewers are global, incoherent and do not take 
> into account the fact that we have already done a lot of work and the 
> budget will likely decrease not increase: (1) change package for the 
> AMchip, (2) go to 130 nm IBM instead of 65 nm TSMC, (3) use serial 
> links in the board instead of parallel buses, (4) get 30% more money 
> (actually if we go to serial links we need 400% more money)......  all 
> this is totally not realistic for our plan to be able to measure 
> consumption, cooling and performances in 2012. Before doing 
> production, we need probably 2-3 AMChip prototypes, it requires time.
>
> (3) using VME we are compatible with the vertical slice, what we do 
> for the vertical slice is automatically good for the system. If we go 
> to ATCA all the work we do with the vertical slice is unuseful. We do 
> not have the manpower.
>
> (4) we already have 2 new VME crates, 2 new CPUs  in the lab, we 
> cannot put them in hold.
>
> (5) we are measuring the consumption and it seems to be less than 
> expected, may be a factor 2. This reduces a lot concerns  about 48 V 
> (2 pins could be enough and separate GND return could be available).
>
> I really think ATCA for the core crate for 2015 is not feasible, 
> especially if in the same time we have to take data with the vertical 
> slice. Too much work in a too short time.
> It is an interesting option for phase II. The LAMB will be redesigned 
> for that time, with new chips, new packages and new serial links.
>
> Regards
>                            Paola
>
>
>
> Mel Shochet wrote:
>>      There are now two suggestions for moving to ATCA.  Interboard 
>> data transfer in the Data Formatter crates could be made easier (the 
>> alternative being fibers between boards).  The Initial Design Review 
>> committee recommends that we consider ATCA for the core crates 
>> because of the committee's concern about power (our 48-volt solution) 
>> and cooling.  We will have to respond to this suggestion.  (A 
>> potential disadvantage is ATCA's 8U vs VME's 9U size).  Could we have 
>> an initial discussion of the issue at our meeting in 2 weeks (April 
>> 5)?  We could hear what the DF issues are from Fermilab and what the 
>> core crate issues are from someone in Italy working on the AM and 
>> associated infrastructure.  Then we can decide on the next steps if any.
>>
>>                         Regards,
>>                         Mel
>>
>>
>>
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