ClusterAlg.gif (577 bytes) The ATLAS Level-1 Calorimeter Trigger

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TDR Updates - Technologies

This page provides information on changes to the calorimeter trigger design made after submission of the TDR. Information on changes to TDR Algorithms and External Systems is also available.

Data transmission from Pre-processor.

TDR - Pages 124-125,205-207 Updated Version
Data is transmitted using Hewlett-Packard G-Link chips running at 40 MHz with 20-bit data width LVDS data is carried between 10-bit National Semiconductor DS92LV1021(Tx), DS92LV1210 chips. Power per 20-bit link is reduced at the Pre-processor from 1.9W to 0.2W  and at the em/tau and Jet/energy processors from 2.5W to 0.3W. G-Link use is still planned for the asynchronous data and RoI readout to RODs.
Presented: CERN Level-1 meeting 23-Feb-1999 (E Eisenhandler) , Calorimeter Trigger Collaboration Meetings at Birmingham March 1999, RAL July 1999 and Stockholm November 1999.
Status: Agreed. Meets approval criteria: for 8 channels over two 15-metre Datwyler cables connecting two racks, in a 2-hour long run one channel had   one error and the other 7 were error free. Error rate < 10E-12. Similar results were obtained using two 10-metre AMP cables. However, it is clear that great care must be taken over noise and clock purity.

This page was last updated on 16 December, 2013
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