Download - PCI-E X4: status report

CERN, 15 April, 2008 TDAQ Working Group 1

PCI-E X4: status report

Two boards currently being mounted

Next week tests

• 12 layer (6 routing)

• FPGA 780 pin with embedded transceivers

• 2100 nets, 2400 vias, 12 power supplies, controlled impedance

• 2.5 gbit/s lines

• DDR2


Board mounted (side A)


Fit results with quartus

18k Logic Elements available for the user


Parameters

• LKr readout (depending on readout implementation)

• CTP interface (the board can act as a CTP coprocessor: 18k Logic Elements free)

• TELL1 readout

• PCI-E - 4 lines – 16 bit @ 125 MHz (2.0 gbit/s) per lane

• Optical link – 4 TLK2501 – 16 bit @ 75-125 MHz (1.2-2.0 gbit/s)

• Copper link – 2-4 DS90CR485 – 48 bit @ 66-133 MHz (3.1-6.3 gbit/s) – maximum working frequency depends on cable length

Can be used for


LKr trigger proposal

Assumptions:

• 216 LKr readout boards (64 channels per board)

• Digital sum on 4x4 cells on the readout boards

Trigger concentrator boards• Receives 16 readout boards• Peak finding in space and time• Pulse reconstruction with 1-2 ns time resolution• Trigger primitives sorting and propagation to CTP


1 116 116 1

RO board (CERN): digitization + RO4x4 ch digital sum

1st layer Trig board: cluster reconstrtrig prim gener

2nd layer Trig board:

sortinginterface to CTP

RO boa

rd

(CER

N)

Trig

ger b

oard

Trig

ger b

oard

64 ch4 ch 1024 ch

216 x 16 x 1 x

CTP

• 16 optical input

• 1 optical output

• 9U x 400 mm

LKr Trigger: architecture


Pulse reconstruction in FPGA (1-2 ns)


LKr trigger: implementation•The best solution would be to design a completely new system

•A good compromise is to use the existing TELL1 board as a motherboard and design only the interconnections (implemented with TLK2501 + optical transceiver)

•TELL1 was designed some years ago with (now) old components

•TELL1 exists and is working

•We know it (working on LHCb TELL1 muon firmware)

•We already used TLK2501 + optical txrx in an R&D project

OUR STRATEGY

Design a prototype LKr trigger with TELL1 and all the interconnect implemented with TLK2501 + optical transceiver (to minimize design effort).Once it works, if we have time and if needed start the design of the new motherboard


Throughput estimation

• 30 MHz istant/13k cell ~ 150 kHz/board -> average!

• Our conservative assumption is 10 x average in the central region = ~ 1.5 MHz/board

• 16 bits x 4 pads x 8 samples @ 1.5 MHz = ~ 800 Mbit

-> we can work with 4x4 pads and a TLK2501!


TELL1 board

24 optical input


How can we perform halo expansion with TELL1?

• If we work without halo expansion -> 1 optical link for RO card, up to 24 optical input on the trigger concentrator (TELL1)

• If we want halo expansion on the TELL1 we can try the following approach:

each RO card equipped with 1 optical link + 8 lemo out + 8 lemo in cables -> if a seed is found in a RO card one or more neighboring RO cards are flagged for transmission

24 TELL1 input arranged as 16 input + 4 bidirectional links (halo expansion between two different TELL1s) to be checked!


Why to design a new board?

Pulse time reconstruction is a typical DSP application

Altera Stratix III (E version) with embedded DSP

Download - PCI-E X4: status report

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