Exploring a CPLD/FPGA-based Triggering System for LCLS

Matthew T. BrownOffice of Science, Science Undergraduate Laboratory Internship Program

Advisor: Ron Akre

CPLD/FPGA Basics

Gates Macrocells LUTs JTAG Programmer Xilinx ISE

Xilinx Cool Runner XPLA XCR3064XL

Xilinx Spartan 3 XC3S200PQ208-5

The Task at Hand

360Hz fiducial signal Set delays Triggering requirements

– Delay– Pulse length– Jitter

How It’s Done

24-bit counter Comparators Flip flops Design entry

– Schematic – Text (VHDL code written for 8 channels)

Simple Timing Diagram

Schematic Example

CPLD Results

Not good enough!

FPGA Results

FPGA Results Strike Back

Jitter measured to be below 2 picoseconds

Return of the FPGA Results

Onboard Arcturus Coldfire Processor

Four DCMs on the chip allow for sub-clock cycle phase adjusting for the triggers

Conclusion and Possible Future Work

CPLD = No

FPGA = Yes

Need to:– Build a board with all 8 channels on it– Complete the computer-FPGA interface

Acknowledgements

Thanks to Ron Akre, Jeff Olsen, Bo Hong, and Anatoly Krasnykh for help on this project.

Thanks to Steve Rock, Susan Schultz, and Farah Rahbar for managing us kids and the SULI program at SLAC.

Questions?

Sources:– http://supercomputing.fnal.gov/slac_logo.jpg– http://images.amazon.com/images/P/6305428387.01.LZZZZZZZ.jpg– http://therawfeed.com/pix/this_is_sparta.jpg