The Trigger MotherBoard (TMB) combines functions of finding muon stubs
using cathode strip data (CLCT ="Cathode Local Charged Track") and combining
the muon stubs found in cathode view (CLCT) together with stubs found in
anode view (ALCT).
Each TMB board handles triggering for one Cathode Strip Chamber. They are mounted in 9U VME-style crates located on the periphery of the endcap iron disks of CMS. Each peripheral crate contains electronics for 9 chambers: in ME1, this covers a 30o trigger sector, while in ME2, ME3, or ME4 that covers a 60o trigger sector. There are thus nine TMB boards per peripheral crate. A prototype (TMB2001) is shown below:
The CLCT part of the Trigger Motherboard decodes the pattern of
cathode
hits from the CFEBs, and finds half-strip hit patterns in the six-layer
chambers that are consistent with high-momentum muon tracks:
The TMB part of these boards performs a time coincidence of anode
and
cathode LCT information, and when a coincidence is found, sends the
information
to the MPC board described below. In the case of multiple LCTs, the TMB
can select up to two based on quality cuts. Provision has also been
made
for the TMB to allow a possible coincidence of LCT positions with RPC
hits
in the case that two or more LCTs are found and would otherwise produce
ghost hits. Upon receipt of a Level 1 Accept signal (L1A), the anode
LCT,
cathode LCT, and raw hits information is sent through FIFOs to the
DAQMB
(Data AQuisition MotherBoard).
Previous TMB2001mod, for near-final prototyping: