PLX Gen 2 Testing over “16 / 30” Tyco Comm Backplane

1PLX ConfidentialPLX Confidential

PLX Gen 2 Testing over “16 / 30” Tyco Comm Backplane

PLX Gen 2 Testing over “16 / 30” Tyco Comm Backplane

PLX Applications and MarketingPLX Applications and Marketing


IntroductionIntroduction

Introduction – PCIe of 30” Legacy BackplaneThis paper demonstrates the ability of PLX Gen2 switches to linkand operate with over 30 inches of a legacy Communication space (Tyco) backplane at both 2.5 and 5Gbps. In the communications space, the ability to drive distance and the ability to operate without a common clock reference are important factors for these systems. Both these conditions are set up and demonstrated. Link operation was established with approximately 40 total inches of PCB, multiple Hm-Zd and SMA connectors including approximately 2 feet of coax.

Introduction – PCIe of 30” Legacy BackplaneThis paper demonstrates the ability of PLX Gen2 switches to linkand operate with over 30 inches of a legacy Communication space (Tyco) backplane at both 2.5 and 5Gbps. In the communications space, the ability to drive distance and the ability to operate without a common clock reference are important factors for these systems. Both these conditions are set up and demonstrated. Link operation was established with approximately 40 total inches of PCB, multiple Hm-Zd and SMA connectors including approximately 2 feet of coax.


Tyco BackplaneTyco Backplane


Test ObjectiveTest Objective

Use a common Telecom platform to demonstrate PLX Gen 2 reach capabilities

Tyco “16/30” Backplane common ‘figure of merit’• PCB Nelco 4000 material. • Stripline, 6 mil trace, ½ ounce copper• Paddle cards ~ 3 inch trace, Nelco. Stripline• Backplane Connector – Hm-Zd

Two PLX based interconnect solutions• PCIe Connector (RDK) based• SI Reference Card (SMA) based

PLX devices connected to each side of the LinkLink run asynchronously – No forwarded clock Independent clock recovery on each sideLink up over both backplane configurations achieved

Use a common Telecom platform to demonstrate PLX Gen 2 reach capabilities

Tyco “16/30” Backplane common ‘figure of merit’• PCB Nelco 4000 material. • Stripline, 6 mil trace, ½ ounce copper• Paddle cards ~ 3 inch trace, Nelco. Stripline• Backplane Connector – Hm-Zd

Two PLX based interconnect solutions• PCIe Connector (RDK) based• SI Reference Card (SMA) based

PLX devices connected to each side of the LinkLink run asynchronously – No forwarded clock Independent clock recovery on each sideLink up over both backplane configurations achieved


PCIe Connector (RDK based)PCIe Connector (RDK based)


Channel ObservationChannel Observation

Channel plots Non-Inclusive of last PCIe ConnectorChannel plots Non-Inclusive of last PCIe Connector


PCIe Connector (RDK) based ResultsPCIe Connector (RDK) based Results

Gen 1 Linkup established at both “16 and 30”Default switch settings all that requiredTotal distance is ~ 41 inches of PCB + coaxMultiple transitions thru PCB,PCIE,SMA connectors

• Reflections, crosstalk, loss difficult to manageGen 2 Linkup established at “16 inches”

Tested overnight without bit errorTX swing slightly reduced. De-emphasis increased.

• ~600mV vs 650mV, ~10dB TX eq vs ~7.5dB RX EQ at defaultTotal effective link distance ~ 27 inches

• Channel Loss ~ 6dB• Estimated PCB BW on par with Signal BW

Gen 1 Linkup established at both “16 and 30”Default switch settings all that requiredTotal distance is ~ 41 inches of PCB + coaxMultiple transitions thru PCB,PCIE,SMA connectors

• Reflections, crosstalk, loss difficult to manageGen 2 Linkup established at “16 inches”

Tested overnight without bit errorTX swing slightly reduced. De-emphasis increased.

• ~600mV vs 650mV, ~10dB TX eq vs ~7.5dB RX EQ at defaultTotal effective link distance ~ 27 inches

• Channel Loss ~ 6dB• Estimated PCB BW on par with Signal BW


“16 / 30 Inch Testing Gen1”“16 / 30 Inch Testing Gen1”Gen1 Compliance PCIe ConnectorGen1 Compliance PCIe Connector


16 inch Losses16 inch Losses

From WhitepaperFrom Whitepaper


“16” inch Losses-Gen1“16” inch Losses-Gen1Excel ProgramExcel Program


“30” inch Losses-Gen1“30” inch Losses-Gen1

Excel ProgramExcel Program


SI Card based TestingSI Card based Testing


SI Card Based TestingSI Card Based Testing


SI CardSI Card



Gen 2 Linkup established at both “16 and 30” inchesDefault switch settings fine for 16”

• ~ 25” of pcb plus coax“30” inch test used slightly reduced TX swing. De-emphasis increased. (600mv PLX drive / 10dB De-emphasis)

• Linearity more critical than loss with discontinuities• Multiple transitions thru PCB,PCIe,SMA Connectors• No PCIe Connector

Internal RX EQ kept at default• SI card accepts TFT EQ – not needed

Total effective link distance ~ 39 inches + coax• Channel Loss ~ 10 dB• Estimated PCB BW less than Signal BW ( ~1.6 Ghz)

Gen 2 Linkup established at both “16 and 30” inchesDefault switch settings fine for 16”

• ~ 25” of pcb plus coax“30” inch test used slightly reduced TX swing. De-emphasis increased. (600mv PLX drive / 10dB De-emphasis)

• Linearity more critical than loss with discontinuities• Multiple transitions thru PCB,PCIe,SMA Connectors• No PCIe Connector

Internal RX EQ kept at default• SI card accepts TFT EQ – not needed

Total effective link distance ~ 39 inches + coax• Channel Loss ~ 10 dB• Estimated PCB BW less than Signal BW ( ~1.6 Ghz)


Estimated Loss – Gen 2 “30”Estimated Loss – Gen 2 “30”



Documents

PLX Gen 2 Testing over “16 / 30” Tyco Comm Backplane