CC-PC board design guide-lines

This page collects various design guide-lines and recommendations for board-designers implementing a CC-PC. It will be constantly updated. Please mail niko.neufeld@cern.ch about anything you find incorrect, incomplete or missing.

Ethernet

Each board hosting a CC-PC must provide an Ethernet connection. The CC-PCs will be connected to the ECS network via 100BaseT Ethernet (a.k.a as "copper-based" Fastethernet).
The Ethernet Media Access Controller is part of the CC-PC, it is an i82559 (datasheet pdf) from intel. The two differential RX and TX signals need to be connected to an RJ-45 connector on the front-panel. Ethernet requires a suitable magnetic filtering circuit as close as possible to the connector, which is the reason why this filtering must be provided by the carrier board.

We have verified two connector / magnetics combinations, which work with the i82559/CC-PC

1.) An RJ-45 connector with integrated magnetic filtering:
     PulseJack J0035D21B (datasheet pdf) from Pulse Engineering

2.) A discreet magnetic filtering device:
     Botthand 16ST8515 (datasheet pdf)  base pulse transformer from Botthand.
     Find here a drawing of an example circuit.

3) An application note for the 82559 Ethernet chip can be found here,

Pin-Out of the LHCb Connector

The final pin-out of the  glue-card in pdf or Excel format.    NEW 20 February 2004
The mechanical dimensions of the gluecard can be found here.

The glue-card connector to the CC-PC includes all signals which need to be routed between CC-PC and glue-card. Its definition is here.

Dimensions of the LHCb Glue-Card

The dimensions and connector locations of  the LHCb Glue-Card v2.0 can be found here.  The mechanical dimensions and the connector locations can be found here. While there might be slight changes in the future on the board itself, the dimensions and connector locations should not change anymore.

CC-PC Board connector

The following connector is needed to hold a CC-PC on the board:
MOLEX 240 pin (h = 5mm)   Molex Reference Number 53475-2409 (data-sheet)
Alternatively you can use a 53467-2409 (6 mm) or 53481-2409 (7 mm)
The mating connector on the CC-PC is a Molex 240 pin 52760-2409

We have some of these connectors and can provide you with small quantities. If you need any or even better have a good source please write to lhcb-ecs@cern.ch

Power

From the datasheet it is not completely obvious that the CC-PC needs only 5.0 V power supply. The 3.3 V at pin A91 and B91 of J2 are actually outputs (to be used with care, for a total of ~ 1 A). This is made clear in the integration manual V1.6 (section 4.2.5, page 36). The 3.3 V for the core voltage of the CC-PC are generated internally, and will make the D31 LED go on (or at least should, we have seen CC-PCs where this is not the case, although they work!).

RS232 - serial port (COM0)

The CC-PC does not generate the correct levels for the serial port. An additional chip is needed, e.g. the MAX211 (datasheet), which is included on the LHCb Glue-Card. Important: If you do not intend to use the serial port, i.e. you do not have the MAX211 RS232 or equivalent, then you need 4.7k pull-ups respectively pull-downs on the four signals:

CTS1-, DCD1-, DSR1-, RX1 and RI1-

Failing to do so might  halt the CC-PC in the POST (POwerupSelfTest) sequence of the BIOS before the graphics card is initialised - your screen will stay black...

Information for specific pins: clarifications, FAQ etc

Under this heading information concerning specific pins is collected. This information is drawn from experience or from Digital Logic's support

• B13 CORE 3/5 i Only factory: COREBIOS B14 CORE 3/5 i Only factory: VGABIOS
  Only needed to connect external BIOS: leave unconnected

Evaluation Board & reference design:

Schematics of the test-board for the final glue-card are available here

Reset Line

The CC-PCs need an independent means of remote hardware reset. This is achieved by connecting a pin from the rack backplane to a specific pin on the LHCb connector. This note describes the use of these pins.

Please send comments and suggestions to niko.neufeld@cern.ch.