The CLEO-III trigger: level 1 decision and gating

Author

Selen, Mats A. ; Hans, Randal M. ; Haney, Michael J.

Author_Institution

High Energy Phys. Group, Illinois Univ., Urbana, IL, USA

Volume

48

Issue

3

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

562

Lastpage

566

Abstract

The Level 1 decision and data flow control subsystems of the CLEO-III trigger produce and distribute a trigger decision every 42 ns based on input from calorimetry and tracking subsystems. This paper describes the free-running pipelined trigger decision logic that correlates axial and stereo tracking information, and combines time-aligned calorimetry information onto a common backplane. Programmable trigger decision boards monitor this backplane and can be configured as desired to respond to a wide variety of trigger conditions. The resulting trigger decision is regulated by a throttling mechanism that allows the data-acquisition system to modulate the trigger rate to maximize throughput without buffer overrun. A central signal distribution mechanism delivers the trigger decision and system clock to the front-end electronics

Keywords

drift chambers; field programmable gate arrays; nuclear electronics; particle calorimetry; trigger circuits; CLEO-III trigger; data flow control subsystems; free-running pipelined trigger decision logic; front-end electronics; level 1 decision; programmable trigger decision boards; time-aligned calorimetry information; tracking subsystems; Backplanes; Calorimetry; Circuit topology; Clocks; Condition monitoring; Data acquisition; Detectors; Field programmable gate arrays; Logic; Throughput;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/23.940119

Filename

940119