1. A PCI Express Optical Link Based on Low-Cost Transceiver Qualified for Radiation Hardness Andrea Triossi, Diego Barrientos, Damiano Bortolato, Roberto Isocrate, Gabriele Rampazzo, Sandro Ventura and Marco Bellato INFN – Padova and Legnaro
September 18, TWEPP 2012, Oxford, UK

2. Outlines Backgrounds New LINCO Boards Radiation Tests PCI Express
Early Developments
LINCO Project
New LINCO Boards
Block diagrams
Jitter test
Radiation Tests
Transceiver comparison
PCI Express compatibility

3. Backgrounds PCI Express LINCO Project
Gbps/direction transfer rate
De-emphasis
Scalability (up to 32 lanes)
Retransmission of failed packets
Link Training
Quality of service
Differential signaling
PCI address space
Embedded clock (8b/10b)
LINCO Project
Started in 2005
Investigate a new physical medium for the protocol --> optical fibre
Manufacture copper to optical adapters
Assert their effectiveness in a harsh environment

4. Early development PCI to PCI Express optical adapter
PMC form factor
SFP transceivers
PCI Ex / PCI bridge
PCI to PCI Express optical adapter
used in the VME crate of the DT sector collector (CMS)
PCI / VME bridge

5. New development PCI Express (x1 lane) optical translator
Half height – Half length
DMA transfer (128 Byte payload)
Max transfer rate 200 MB/s

6. New development 20 Gbps x4 optical switch PCI Express Gen2
Downstream port x1
Two clock domains:
PCI Express spread spectrum
100 MHz plain clock
Downstream port x1
Downstream port x1
Downstream port x1
Upstream port x4
Downstream port x4

7. MOSFET Power Manager POWR1014A MOSFET DC-DC FPGA Spartan3AN DC-DC
I2C
Differential
DC-DC
FPGA
Spartan3AN
DC-DC
DC-DC
DC-DC
SEL0
SEL1
PERST#
EEPROM
PLX Switch
PEX 8609
PciEx 4x Finger
Mux/Demux
PI2PCIE2412
SFP Transceiver
SFP Transceiver
PCI Ex
Mux/Demux
PI2PCIE2412
SFP Transceiver
REF CLK
CLK Fan-out
PI6C20400S
SFP Transceiver
100 MHz
Oscillator
CLK Fan-out
PI6C20400S

8. Eye diagram 5Gbps Total jitter 0.38 UI @ BER level of 10-12 Test Setup
2 PC linked by 30 meters OF and 2 LINCOs (one non-transparent)
8.5Gbps Finisar transceiver optimized for 4x Fiber Channel
Total jitter 0.38 UI
@ BER level of 10-12

9. Early radiation test Test Setup No SEU! Paul Scherrer Institut
63 MeV proton
Maximum total fluence of ∙1011 p/cm2 ~66Krad
Avarage flux 0.8 ∙108 ~ 2.8 ∙108 p/cm2/s
VME registers continuously written with random patterns, read back and compared
Total absorbed current monitored
No SEU!
Recoverable Micro Latch-up:
Transceiver after 1 Krad
Universe II bridge after 3.5 Krad

10. Single events (2.75∙1011 mean fluence)
Transceiver radiation test
Test Setup
Paul Scherrer Institut with 63 MeV proton
Maximum total fluence of 5∙1011 p/cm2 ~66Krad
Avarage flux 0.8 ∙108 ~ 2.8 ∙108 p/cm2/s
JDS Uniphase
CT2-MS1LBTD32C2
Finisar FTLF8524P2WNL
Infineon
V23848-N305-C56
Intel
TXN31115D2
Laser
VCSEL 1310nm
VCSEL 850nm
Current modulation √ X
Laser driver enabling Tx
1.25∙1011
6.03∙1010
Random jitter
No effect Rx
Single events
(1.25∙1011 mean fluence)
Single events (2.75∙1011 mean fluence)

11. Transceiver radiation test

12. Single events (2.75∙1011 mean fluence)
Transceiver radiation test
Test Setup
Paul Scherrer Institut with 63 MeV proton
Maximum total fluence of 5∙1011 p/cm2 ~66Krad
Avarage flux 0.8 ∙108 ~ 2.8 ∙108 p/cm2/s
JDS Uniphase
CT2-MS1LBTD32C2
Finisar FTLF8524P2WNL
Infineon
V23848-N305-C56
Intel
TXN31115D2
Laser
VCSEL 1310nm
VCSEL 850nm
Current modulation √ X
Laser driver enabling Tx
1.25∙1011
6.03∙1010
Random jitter
No effect Rx
Single events
(1.25∙1011 mean fluence)
Single events (2.75∙1011 mean fluence)

13. PCI Express compatibility
10-12
Eye opening 1
Infineon transceiver is not suitable for PCI Express protocol transmission after a radiation dose of 3.2∙1011 p/cm2

14. Conclusion LINCO Boards Harsh Proton Environment Three flavors
Deployed in several experiments (CMS, AGATA, ICARUS…)
Harsh Proton Environment
Commercial transceivers
Intel and Infineon transceivers got through CMS requirement