1. June 2004 Craig Ogilvie 1 Strip Pilot  Communication link between ladder and counting house  Three optical fibers –Send serialized data –Receive control data –Receive beam clock  Try to put no brains on the board  Goal –Board to be used for barrel outer layers and endcap –If possible, use board design at both IR and counting house Serializer De-serializer Data out Control 16 bit Control/clock bus Data from bus clock

2. June 2004 Craig Ogilvie 2 Strip Requirements (TVC March 04)  Two readout cards (ROC) per sensor –Each ROC has 6 SVX4 + FPGA / ASIC –8 ROCs per ladder –48 svx4 per ladder  Volume per SVX4 –Each hit = 16 bit word –1 header –Total words/svx4 = 1+(num hits) = 1+(occ*128)  Volume per ladder –Total words/ladder = 48+(occ*6144)  Time = (48+(occ*6144))/40 MHz –< 40 microsec if occ < 25%  Serialize each 16 bit word at 40 MHz

3. June 2004 Craig Ogilvie 3 Deserialize  Control bus on ladder is 15 bits wide –Serialize control bits  Use “same” board in counting house –Clock fiber different Serializer De-serializer Data out Control/clock in 16 bit Control/clock bus Data from bus Serializer De-serializer 16 bit Serializer De-serializer 16 bit IR Counting house

4. June 2004 Craig Ogilvie 4 Options for Serializer/Deserializer  GOL –Only serializes  TLK1501 (Texas Instrument) –Serializes/deserializes 16bits @ 30-60MHz »1.2Gbps –TLK2501 serializes @ 125 MHz => 2.5 Gbps –8bit /10 bit coding –Radiation tolerance?  OASE (Heidelberg/Mannheim) –Serializes/deserializes 10bits @ 250MHz »2.5Gbps –On-chip laser diode (VCSEL) –Not yet available

5. June 2004 Craig Ogilvie 5 Endcap Requirements  Each endcap has 4 z-stations and 24 sectors/station –96 pilot cards or output fibers –~6k channels / fiber  PHX hit, minimum of 16 bits  Total words / fiber = (num hits) = occ*6k  Timing for LVL1, data off detector in ~0.5 microsec  Try tlk2501 at max 125 MHz  Time = (occ*6k)/125 MHz –< 0.5 microsec if occ < 1%

6. June 2004 Craig Ogilvie 6 Next Steps  Iterate with Vince, Chi, John H. on requirements, skeleton of design –Work closely with ORNL  Buy TLK1501/TLK2501 samples ($16 / piece) –Test on bench »Serialize/deserialize loop –Test in radiation environment »IR, elsewhere?  Optical components –Depends on location in IR –If on ladder, CMS optical package used by pixel »ST Microelectronics –If on nosecone, many options