Versatile firmware for the Common Readout Unit (CRU) of the ALICE experiment at the LHC

TL;DR

This paper presents the architecture and performance of a versatile firmware framework for the ALICE experiment's Common Readout Unit at CERN, enabling efficient data acquisition and control across multiple sub-detectors.

Contribution

It introduces a flexible firmware framework for the ALICE CRU, supporting various data-taking modes and interfacing with multiple sub-systems in the upgraded LHC experiment.

Findings

Supports continuous and triggered data-taking modes

Reduces data throughput from 3.5 TB/s to 635 GB/s

Demonstrates reliable data flow and system integration

Abstract

As from the run 3 of CERN LHC scheduled in 2022, the upgraded ALICE experiment will use a Common Readout Unit (CRU) at the heart of the data acquisition system. The CRU, based on the PCIe40 hardware designed for LHCb, is a common interface between 3 main sub-systems: the front-end, the computing system, and the trigger and timing system. The 475 CRUs will interface 10 different sub-detectors and reduce the total data throughput from 3.5 TB/s to 635 GB/s. The ALICE common firmware framework supports data taking in continuous and triggered mode and forwards clock, trigger and slow control to the front-end electronics. In this paper, the architecture and the data-flow performance are presented.