Changes between Version 3 and Version 4 of CommonATCA

Timestamp:

May 31, 2018, 4:20:06 PM (6 years ago)

Author:

Eric Hazen

Comment:

--

CommonATCA

@@ -1 +1 @@
 '''2018-05-31'''
 
-Thinking about a common blade for ATLAS L0MDT and CMS IT-DTC.
+Thinking about a common blade for ATLAS L0MDT and CMS IT-DTC. \\
+Issues with the current ATLAS design:
+
+* FMC stacking height at 8.5mm is too high
+
+Issues with the current CMS design (Cornell one):
+
+* Really don't like the interposer concept with metal plates, springs etc
+* Prefer stand-alone mezzanine card operation
+
+Plus, there are two different blade designs for no obvious reason.
 
 First, looking at low stack height connectors, but not Z-ray.  
@@ -18 +28 @@
 Below is a figure with dimensions excerpted from the ATCA standard.
 
-|| [http://gauss.bu.edu/svn/atlas-phase-2-muon-upgrade/Meetings/2018-05-31_EDF/figs/stack_heights.png  [[Image(http://gauss.bu.edu/svn/atlas-phase-2-muon-upgrade/Meetings/2018-05-31_EDF/figs/stack_heights.png)]]] || Seems as if we can find a 4mm or 5mm solution.  \\ This gives us about 15.7mm above a mezzanine board for components. ||
+|| [[Image(http://gauss.bu.edu/svn/atlas-phase-2-muon-upgrade/Meetings/2018-05-31_EDF/figs/stack_heights.png)]] || Seems as if we can find a 4mm or 5mm solution.  \\ This gives us about 15.7mm above a mezzanine board for components. ||
 
+Next, thinking about the logic.  Is it really that hard to make a common blade?  Here are some thoughts:
+
+* Build a blade to accommodate 3 mezzanine cards
+* Plan for only "low speed" mezz-to-mezz communications \\
+  (SelectIO or < 10Gbps SERDES)
+* Mezzanine cards would have the optics on board along with DC/DC converters and regulators
+* Split the CMS IT-DTC into 3 parts
+* Eliminate the "blade FPGA" from the ATLAS design and designate one mezz card as "master" \\
+  (this could be a different design).
+
+