Orsay, 10 december 2009, for the selection process of the trigger and synchronization system for nuclear physics experiments in GANIL (SPIRAL2) Joël Chavas

GTS

Trigger and synchronize : AGATA + ancillaries

Outline

• GTS – Main features • GTS – Hardware / software • GTS – Status and characteristics

The DAQ in AGATA

GTS – Function

• Provides the global clock • Handles centrally all trigger requests • Transport medium for trigger activity • Equalizes downlinks

– No calibration run required • Provides the absolute time (48-bit counter)

GTS – Structure

Trigger processor Root

Leaf

Leaf

Fanin- fanout

Leaf

Leaf

GTS – AGATA requirements

• Individual trigger requests – 50 kHz • Trigger validation – 1 MHz (Mult. 1) • Trigger validation – 300kHz (Mult. 30) • Repeatability of the phase skew on the sub-ns

scale

GTS – Originality and novelty

• Digital trigger system • Replaces analog triggers – without dead-time • Optical fibers, to transmit clock and trigger events • Modularity

Hardware

• Trigger processor : – a commercial card inside a PCIexpress slot of the computer

• GTS card : – Mezzanine – ATCA card in development

• Links : – Optical links – Mezzanine connectors

GTS card

FPGA

PLL

TDC

mux

DELAY

MGT optic M

trigger bus

GTS mezzanine

XXX

GTS mezzanine

GTS mezzanine – on LLP carrier GTS

GTS

GTS mezzanine – On LLP carrier

GTS

Firmware / software

• Trigger processor : – edk project, home made slow control through

PCIexpress • GTS :

– edk project, embedded software (vxWorks) – slow control through udp/ip

How it works : a modular approach

GTS tree

Trigger processor

vhdl trigger cores

Trigger processor – structure

Online sorter

Multiplicity Partition 0

Multiplicity Partition 1

Multiplicity Partition 4

Multiplicity Partition 5

Multiplicity Partition 2

Multiplicity Partition 3

Multiplicity Partition 6

Coincidence Validation broadcast

Multiplicity Partition 7

Trigger processor

• Partition coincidence – Ex : Mult(Ge) ≥ 4 and Mult(Ancillary) ≥ 1 after 5µs – Delayed multiplicity window : clock precision

GTS tree – General

• A unique hardware for all nodes • A unique firmware for all leaves • A unique embedded software for all nodes

GTS tree – Clocks

• Clock recovered from gigabit optical links • Clock cleaned by external PLL • Downlink times are measured • Downlink times are equalized through a FIFO and

an external delay line

GTS tree – Alignment

combinatorial

combinatorial t1

combinatorial

clocked t2

downlink

tdownlink = t2 – 1/2 × t1

GTS – Communication with carriers

Trigger cores

• Handle all trigger activity • Purely vhdl • Uplink :

– Trigger requests – Periodic idles

• Downlink : – Trigger validation – Absolute time – Synchronous command

• No dead-time

Root

Leaf

Leaf Leaf

Leaf uplink

downlink

Measurements – Jitters

p-p jitter (ps)

clk 70

leaf-leaf 200

leaf-root 170

Measurements – Skews

Max (ps)

phase alignment +/- 250

phase repeatability +/- 50

Measurements – latencies

• Local latency : hundreds of ns • No dead-time, except for a technical 2 µs one • GTS tree latencies :

– Max = 12 µs (4-layer tree) with trigger processor • Depends on idle rate and delayed coincidence

– 7 µs without trigger processor – 2 µs added at each FANIN-FANOUT layer

GTS commissioning : november 2009

• 4-layer GTS tree • 7 leaves (6 for germanium detectors, 1 for

ancillary detectors) • 2 partitions (germanium detectors and ancillary

detectors) with two decision equations used : – Mult(Ge, 3,+0) – Mult(Ge,2,+0) + Mult(Anc,1,+2µs)

• Technical trigger validation rate : 2 MHz

Trigger processor -- Status

• 2 multiplicity partitions implemented on a FX100 • Firmware done for 8 partitions – to be

implemented on a more powerful hardware • On-line reconfiguration through a pseudo-C

configuration file • GUI based on ncurses library

GTS tree -- Status

• Done : firmware, embedded software, host server software

• Under development : python-based GUI • ATCA card development

GTS hardware – Status

• V2 : 4 complete GTS cards + 1 GTS that can be used only as root

• V3 : 20 produced and tested • V3 : 10 under production for june 2009 • Comments :

– Production is not the problem : testing and support are the problem

– Stand-alone GTS card : no support is needed – GTS tree : support is needed

Discussion and future needs

• Ancillaries and the GTS tree latency • Feeding the root and the leave with an external

clock – links with BUTIS? • Customization (software) of the trigger processor

– Physics is done on the trigger processor

Work load

• Roberto Isocrate (hardware) • Damiano Bortolato (firmware/software GTS tree

prototype) • Joël Chavas (firmware/software/commissioning GTS tree,

testing) • Luciano Berti (trigger processor) • Marco Bellato (trigger cores, conception, organization) • Dino Bazzacco (validation)

Conclusion

• GTS : an innovative digital trigger system • Successful commissioning with the ancillary

detectors included : november 2009