A large associative memory system for the CDF level 2 trigger

A large Associative Memory system for on-line track reconstruction in a hadron collider experiment has been designed, prototyped and tested. This is the first such application of the Associative Memory concept and it is based on a full custom VLSI chip developed within this project. The Associative Memory is the heart of the Silicon Vertex Tracker, which is part of the Level 2 trigger of the CDF experiment, and is able to complete track finding in the CDF silicon vertex detector less then 1 μsec after detector readout is over. This system is a multi-board project running on a common 30 MHz clock, but critical parts multiply clock frequency to operate up to 120 MHz. The Associative Memory board architecture, design, implementation and test are described. The main characteristics of this project are the use of sophisticated clock distribution techniques and the high density of components