학술논문

The ATLAS level-1 calorimeter trigger architecture
Document Type
Periodical
Source
IEEE Transactions on Nuclear Science IEEE Trans. Nucl. Sci. Nuclear Science, IEEE Transactions on. 51(3):356-360 Jun, 2004
Subject
Nuclear Engineering
Bioengineering
Field programmable gate arrays
Merging
Hardware
Coordinate measuring machines
Data acquisition
Costs
Backplanes
Large Hadron Collider
Timing
Control systems
Language
ISSN
0018-9499
1558-1578
Abstract
The architecture of the ATLAS Level-1 Calorimeter Trigger system (L1Calo) is presented. Common approaches have been adopted for data distribution, result merging, readout, and slow control across the three different subsystems. A significant amount of common hardware is utilized, yielding substantial savings in cost, spares, and development effort. A custom, high-density backplane has been developed with data paths suitable for both the em//spl tau/ cluster processor (CP) and jet/energy-summation processor (JEP) subsystems. Common modules also provide interfaces to VME, CANbus and the LHC timing, trigger and control system (TTC). A common data merger module (CMM) uses field-programmable gate arrays (FPGAs) with multiple configurations for summing electron/photon and /spl tau//hadron cluster multiplicities, jet multiplicities, or total and missing transverse energy. The CMM performs both crate- and system-level merging. A common, FPGA-based readout driver (ROD) is used by all of the subsystems to send input, intermediate and output data to the data acquisition (DAQ) system, and region-of-interest (RoI) data to the level-2 triggers. Extensive use of FPGAs throughout the system makes the trigger flexible and upgradable, and several architectural choices have been made to reduce the number of intercrate links and make the hardware more robust.