Strategy for unified data link Zhen-An LIU Institute of High Energy Physics

New Ideas on Belle II DAQ Consideration Base –HS data transmission –Optical link –Unified Readout –Unified Data link –Also trigger? –Also timing? My talk on PMC/COPPER link

Trigger path suggestion to Iwasaki-san If HS data link used –RocketIO (SEDES) –Synchronization needed (per channel) –Channel Alignment needed (per system) –Pipelined processing Trigger latency should reserve big enough –5 us maybe enough but conservative –7 us in BESIII Trigger distribution –More time needed

Scheme1 for Data link (to Copper) Based on discussions two schemes in consideration Scheme 1 –Detector specific readout( Gary’s board or other?) 16 ch/optical line Data preprocessing Partial packaging Data frame/protocol Length/ch/event? Trigger L1 driven –Data merger Further packaging Necessary to save COPPER boards Output to COPPER PMC Data frame2 –PMC Data mover to CPU on COPPER

VME BUS Clock (40MH z) Test output Reserved 95 Con 95 Con 5V/3.3V Bus Switch IDT QS Optical Fiber 9 HFBR5921L 0 HFBR5921L 9 HFBR5921L 1 Optical Fiber 1 Optical Fiber 8 HFBR5921L 8 34 Pin LVDS 34 Pin LVDS SN75LVDS387 LVTTL-LVDS SN75LVDS387 LVTTL-LVDS 16*12 Test Pins 16 Test Pin Power Supply LT1764EQ-DD 1.5V,2.5V,3.3V,5V 1.6~2.5V Adjustable LED Display D(0:31) SN74 ALVTH D(0:31) SN74ALVTH MC100 EP16FD CDCF MHz XC2VP40 FF Download circuit 1.6 GBps /ch Merger test module From Unified Readout To COPPER PMC Control Signals Via USER pins Optical Fiber0

To be decided with Scheme 1 Clock for HS transmission System clock How many input ch / board? –Data rate –Data size VirtexII Pro / VirtexV ? Synch/Asych? –Synchronized data transmission. Data frame

Status Hardware available –Data source –Merger board –Test system available Protocol –Need FRST, Tsync signals from timing sys. –Need more discussion with timing/readout/COPPER people PMC to be designed

Scheme2 for Data link In scheme 1: –Optical transceiver inside detector( say CDC) –Question: Reliability not so good in BESIII –Radiation? Experiment did before design –ESD effect? Experiments under taken –Unclear yet! Stop machine for replacement? Open the Detector for replacement? –Possible solution Optical transceiver outside detector Merger before HS data link

Scheme2 for Data link Scheme 2 –Merger near detector –Electrical to FEE –Optical to PMC/COPPER –Easy maintenance –SFP transceiver

More discussion scheduled A discussion is scheduled tomorrow Idea from detector and FEE welcome