Leo Greiner IPHC DAQ Readout for the PIXEL detector for the Heavy Flavor Tracker upgrade at STAR

Leo Greiner IPHC DAQ Talk Structure Review of Sensor development and coupled RDO development System design Detailed system structure Data Rates Ultimate sensor system discussion

Leo Greiner IPHC DAQ IPHC Functional Sensor Development Data Processing in RDO and on chip by generation of sensor. The RDO system design evolves with the sensor generation. 30 x 30 µm pixels CMOS technology Full Reticule = 640 x 640 pixel array Mimostar 2 => full functionality 1/25 reticule, 1.7 ms integration time (1 MHz clk), analog output. (in hand and tested) All sensor families: Phase-1 and Ultimate sensors => digital output (in development)

Leo Greiner IPHC DAQ System Design – PIXEL Structure Current Conceptual Design ALICE Style Structure – carbon fiber box beam 10 sensors / ladder 4 ladders / carrier unit 10 carrier units in the detector -1 < eta < 1 Inner radius ~ 2.5 cm Outer radius ~ 8.0 cm

Leo Greiner IPHC DAQ System Design – System Blocks This is a highly parallel system – a schematic representation is shown below.

Leo Greiner IPHC DAQ m – Low mass twisted pair 3 m - twisted pair System Design – Physical Layout Sensors, Ladders, Carriers (interaction point) LU Protected Regulators, Mass cable termination RDO Boards DAQ PCs Magnet Pole Face (Low Rad Area) DAQ Room Power Supplies Platform 30 m 100 m - Fiber optic cables

Leo Greiner IPHC DAQ Detailed System Structure – Sensors and Cables Early prototype cable with 40 differential pair output, clock and control routed under sensor area. 4 LVDS outputs / sensor Cable 4 layer micron thickness Aluminum Conductor Radiation Length ~ 0.1 % 40 LVDS pair signal traces Clock, JTAG, sync, marker Fine twisted pair cables 125 micron diameter wire Soldered directly to cable Low stiffness / mass

Leo Greiner IPHC DAQ Detailed System Structure – LU Protection and Mass Termination 1 Main Board per carrier 10 carriers in the PIXEL detector

Leo Greiner IPHC DAQ Detailed System Structure – RDO Board(s) New motherboard Two board System – Virtex-5 Development board mated to a new HFT motherboard Xilinx Virtex-5 Development Board Digital I/O LVDS Drivers 4 X >80 MHz ADCs PMC connectors for SIU Cypress USB chipset SODIMM Memory slot Serial interface Trigger / Control input FF1760 Package 800 – 1200 I/O pins 4.6 – 10.4 Mb block RAM 550 MHz internal clock Note – This board is designed for development and testing. Not all features will be loaded for production.

Leo Greiner IPHC DAQ Detailed System Structure – RDO Functional Data Path – Phase 1

Leo Greiner IPHC DAQ Detailed System Structure – RDO Function Data Path – Ultimate Assumptions – Data sparsification with rolling shutter architecture. Output from sensor is a series of addresses – BUT – processing / readout time varies with event occupancy. Addition of a trigger input and a frame marker flag that strobes one frame after receipt of a trigger input. But this needs to be pipelined as well. Other simpler methods are also possible.

Leo Greiner IPHC DAQ Detailed System Structure – RDO Functional Data Path – Ultimate

Leo Greiner IPHC DAQ Detailed System Structure – System Level Functioning

Leo Greiner IPHC DAQ Data Rates - Parameters Rates as per Jim Thomas, L = 3 x for Phase-1, L = 8 x for Ultimate. 2.5 hits / cluster. 1 kHz average event rate. 10 inner ladders, 30 outer ladders. Factor of 1.6 for event format overhead (can be lowered). No run length encoding R = 2.5R = us 640 us Hits / Sensor at L = 8 x Integration Time Radius

Leo Greiner IPHC DAQ Data Rates Ultimate => 49.7 MB / s raw addresses. => 79.5 MB / s data rate. Phase–1 => 59.6 MB / s raw addresses => 95.4 MB / s data rate. The dead-time is primarily limited by the number of externally allocated readout buffers!

Leo Greiner IPHC DAQ Data Rates – Dead time and Latencies Average Ultimate inner sensor event size is 3.1 kb. RDO at 160MHz on 1 LVDS link / sensor takes 19.4 us (< 200 us integration time) What is the latency for data sparsification? If the system were dead during the integration time (after trigger) and one serial RDO time we would be 21.9% dead at 1 kHz. Look for ways to improve, earlier method is just one.

Leo Greiner IPHC DAQ Ultimate Sensor System Discussion The design of the Ultimate SYSTEM should be an integrated design with the sensor and RDO designed to complement each other's capabilities. Question – is it advantageous to use the processing capabilities inherent in an FPGA based RDO system to offload some of the functionality of the sensor? Would this help the overall system design?

Leo Greiner IPHC DAQ fin