7
Ken Wyllie 1 LHCb Electronics Brainstorm 24 th February 2009

LHCb Electronics Brainstorm

  • Upload
    sabine

  • View
    27

  • Download
    0

Embed Size (px)

DESCRIPTION

LHCb Electronics Brainstorm. Summary of ROUGH link estimate from sub-dets. Rough estimate for optical links in existing LHCb = 1.1 MCHF. Trigger superviser. Trigger superviser. hardware trigger. hardware trigger. Architecture with ZS. Data. HLT++. Data. HLT++. Buffering with ZS - PowerPoint PPT Presentation

Citation preview

Page 1: LHCb  Electronics Brainstorm

Ken Wyllie 1

LHCb Electronics Brainstorm

24th February 2009

Page 2: LHCb  Electronics Brainstorm

Ken Wyllie 24th February 20092

Summary of ROUGH link estimate from sub-dets

Non zero-supp NZS Zero supp ZSSubdet # GBT @ 3.2 Gbit/s # GBT @ 3.2 Gbit/sVelo 8652 1176ST 31200 1200OT 6500 3500RICH 6292 1736Calo 1920 750Muon - -Total 54,564 8,362

Assuming “300 CHF per link”Cost CHF 16.5 MCHF 2.5 MCHF

Rough estimate for optical links in existing LHCb = 1.1 MCHF

Page 3: LHCb  Electronics Brainstorm

Ken Wyllie 24th February 20093

Architecture with ZS

hardwaretrigger

Triggersuperviser

Data

HLT++

hardwaretrigger

Triggersuperviser

Data

HLT++

Page 4: LHCb  Electronics Brainstorm

Ken Wyllie 24th February 20094

FE derandomising bufferAbsorb statistical fluctuations in dataNeeds careful monitoringNeeds careful simulation

BE input bufferLength = trigger latency+ margin for derandomiser

BE trigger bufferSmall, re-ordering?

BE output bufferDepends on output protocoleg MEP factor?

Buffering with ZSTriggering = BX correspondence

Page 5: LHCb  Electronics Brainstorm

Ken Wyllie 24th February 20095

Data Structure from front-end

Define maximumlag between Bx andtransmission time.if exceeded, Þ start truncating

Page 6: LHCb  Electronics Brainstorm

Ken Wyllie 24th February 20096

Modularity – something to think about . . . .Example:

Page 7: LHCb  Electronics Brainstorm

Ken Wyllie 24th February 20097

Thoughts & Discussion

Clear cost saving in links by zero-suppressing in the front-ends-----------------------------------------------------------------------------------Need to implement front-end buffers after ZS

- carefully monitor event size and time lagEvent-sizes & statistical fluctuations have to be well understoodAdditional bandwidth overhead with ZS on front-end

- transmit BX (12 bits?)- transmit buffer status

Programmable devices would be very useful ! ! !-----------------------------------------------------------------------------------Interaction trigger/throttle decisions based on BX-ID tagsTELL40: buffer management + DAQ formatting-----------------------------------------------------------------------------------Existing Muon system is non-ZS: plan was to use this system

Fron

t-en

dBa

ck-

end