'Conference Website:


Two pages, to be printed and posted one above the other. As presented at IEEE.

Abstract and Summary

'Title: Hardware Aspects of the Upgraded D0 Central Track Trigger


The D0 experiment at the Tevatron at Fermilab (Batavia, IL USA) was recently upgraded to handle the expected increase in instantaneous Tevatron luminosity for Run IIb. As part of the upgrade, much of the Level 1 Central Track Trigger system was replaced.

A key element in the Central Track Trigger is the Digital Front-End (DFE) system. The DFE processes hits from the Central Fiber Tracker and identifies track candidates by comparing fiber hits to predefined hit patterns using combinatorial logic implemented in FPGAs. The original DFE worked well but suffered several limitations: It combined pairs of fibers in the tracker on a single input to the track-finding logic; it required a long elapsed time to download new firmware; and the cable plant at the front of the DFE racks was difficult to manage.

The new DFE system provides many improvements, while remaining plug-compatible with the orignal. It significantly improves granularity in the track-finding logic, provides much faster firmware update times, and eliminates completely the cable plant at the front of the DFE racks. A new controller module provides a gigabit ethernet over optical fiber interface for control and initialization. New self-test features permit exercise of all DFE logic with pre-programmed test patterns, allowing a complete test of each DFE crate before installation. A stand-alone tester was developed to exercise all inputs and outputs of each DFE for design verification and production testing.


Reference Material

There is a previous IEEE submission linked from here and a poster: