1. Readout Firmware of the Vertex Locator for LHCb Run 3 and Beyond
- Author
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Mark Richard James Williams, Pawel Jalocha, Kurt Rinnert, Francesco Dettori, Pawel Kopciewicz, John Back, Malcolm John, Jan Buytaert, T. J. V. Bowcock, Timothy Gershon, Michael Joseph Morello, B. Rachwal, Nathan Jurik, Kristof De Bruyn, Karol Hennessy, Elena Dall' Occo, Jaap Velthuis, Andrew J. Morris, Victor Coco, Irina Nasteva, Federico Lazzari, Abraham Gallas Torreira, Maciej Witold Majewski, Pablo Vazquez Regueiro, Christopher Parkes, Daniel Hynds, Donal Murray, M. Ferro-Luzzi, Martin van Beuzekom, Timothy Evans, Stefano De Capua, Giovanni Punzi, Vladimir Volkov, Larissa Helena Mendes, Karlis Dreimanis, Deepanwita Dutta, Gabriel Rodrigues, Manuel Schiller, Antonio Fernandez Prieto, Igor Kostiuk, Lucas Meyer Garcia, Lars Eklund, Marcel Merk, Luke Scantlebury-Smead, Silvia Borghi, Edgar Lemos Cid, P. Collins, Peter Svihra, Galina Bogdanova, Aleksandra Snoch, Kazu Akiba, Tara Shears, Alexander Leflat, Oscar Augusto, Vinicius Franco Lima, Sneha Naik, Wouter Hulsbergen, Tomasz Szumlak, David Hutchcroft, Agnieszka Oblakowska-Mucha, Heinrich Schindler, Dana Bobulska, Juan Otalora, Franciole Da Cunha Marinho, Cristina Sanchez Graz, T. E. Latham, Beatriz Garcia Plana, Oscar Boente Garcia, Marco Gersabeck, Giovanni Bassi, Hennessy, Karol, Prieto, Antonio Fernandez, Regueiro, Pablo Vazquez, Buytaert, Jan, Van Beuzekom, Martin, Cid, Edgar Lemo, Eklund, Lar, de Bruyn, Kristof, Naik, Sneha, Schiller, Manuel, Murray, Donal, Leflat, Alexander, Bassi, Giovanni, Punzi, Giovanni, Lazzari, Federico, Morello, Michael J., Garcia, Oscar Boente, Torreira, Abraham Galla, Plana, Beatriz Garcia, Bowcock, Themi, Dettori, Francesco, Dreimanis, Karli, Lima, Vinicius Franco, Hutchcroft, David, Rinnert, Kurt, Shears, Tara, Augusto, Oscar, Coco, Victor, Collins, Paula, Evans, Tim, Ferro-Luzzi, Massi, Schindler, Heinrich, Akiba, Kazu, Occo, Elena Dall', Graz, Cristina Sanchez, Hulsbergen, Wouter, Hynds, Daniel, Kostiuk, Igor, Merk, Marcel, Snoch, Aleksandra, Bobulska, Dana Seman, Borghi, Silvia, de Capua, Stefano, Dutta, Deepanwita, Gersabeck, Marco, Parkes, Chri, Svihra, Peter, Williams, Mark, Bogdanova, Galina, Volkov, Vladimir, Kopciewicz, Pawel, Majewski, Maciej, Oblakowska-Mucha, Agnieszka, Rachwal, Bartlomej, Szumlak, Tomasz, Garcia, Lucas Meyer, Marinho, Franciole, Mendes, Larissa Helena, Nasteva, Irina, Otalora, Juan, Rodrigues, Gabriel, Velthuis, Jaap, Jalocha, Pawel, John, Malcolm, Jurik, Nathan, Scantlebury-Smead, Luke, Back, John, Gershon, Tim, Latham, Tom, and Morris, Andrew
- Subjects
Nuclear and High Energy Physics ,Large Hadron Collider ,Computer science ,Firmware ,business.industry ,Settore FIS/01 - Fisica Sperimentale ,Detector ,vertex locator (VELO) ,computer.software_genre ,DAQ ,Computing and Computers ,LHCb ,Data acquisition ,firmware ,Nuclear Energy and Engineering ,Application-specific integrated circuit ,Gigabit ,readout ,Detectors and Experimental Techniques ,Electrical and Electronic Engineering ,Serializer ,business ,Field-programmable gate array ,computer ,Computer hardware - Abstract
The new LHCb Vertex Locator (VELO) for LHCb, comprising a new pixel detector and readout electronics, will be installed in 2021 for data taking in Run 3 at the LHC. The electronics centers around the "VeloPix" ASIC at the front-end operating in a trigger-less readout at 40MHz. A custom serializer, called gigabit wireline transmitter (GWT), and associated custom protocol have been designed for the VeloPix. The GWT data are sent from the serializers of the VeloPix at a line rate of 5.12 Gb/s, reaching a total data rate of 2-3 Tb/s for the full VELO detector. Data are sent over 300-m optic-fiber links to the control and readout electronics cards for deserialization and processing in Intel Arria 10 FPGAs. Because of the VeloPix trigger-less design, latency variances up to 12 mu s can occur between adjacent datagrams. It is therefore essential to buffer and synchronize the data in firmware prior to onward propagation or suffer a huge CPU-processing penalty. This article will describe the architecture of the readout firmware in detail with focus given to the resynchronization mechanism and techniques for cauterization. Issues found during readout commissioning, and scaling resource utilization, along with the their solutions, will be illustrated. The latest results of the firmware data-processing chain can be presented as well as the verification procedures employed in simulation. Challenges for the next generation of the detector will also be presented with ideas for a readout processing solution. The new LHCb Vertex Locator (VELO) for LHCb, comprising a new pixel detector and readout electronics, will be installed in 2021 for data taking in Run 3 at the LHC. The electronics centers around the 'VeloPix' ASIC at the front-end operating in a trigger-less readout at 40MHz. A custom serializer, called gigabit wireline transmitter (GWT), and associated custom protocol have been designed for the VeloPix. The GWT data are sent from the serializers of the VeloPix at a line rate of 5.12 Gb/s, reaching a total data rate of 2-3 Tb/s for the full VELO detector. Data are sent over 300-m optic-fiber links to the control and readout electronics cards for deserialization and processing in Intel Arria 10 FPGAs. Because of the VeloPix trigger-less design, latency variances up to 12 $\mu \text{s}$ can occur between adjacent datagrams. It is therefore essential to buffer and synchronize the data in firmware prior to onward propagation or suffer a huge CPU-processing penalty. This article will describe the architecture of the readout firmware in detail with focus given to the resynchronization mechanism and techniques for cauterization. Issues found during readout commissioning, and scaling resource utilization, along with the their solutions, will be illustrated. The latest results of the firmware data-processing chain can be presented as well as the verification procedures employed in simulation. Challenges for the next generation of the detector will also be presented with ideas for a readout processing solution.
- Published
- 2021
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