Galfa Spectrometer Jeff Mock, Dan Werthimer Jeff Mock, Dan Werthimer Students: Henry Chen, Pavel Monat, Aaron Parsons, Wonsop Sim Science Advisors: Carl Heiles, Snezana Stanimirovic

Image Rejection 45 dB at MHz45 dB at MHz 40 dB at +-20 MHz40 dB at +-20 MHz 35 db at +-30 MHz35 db at +-30 MHz

Gain Control 0 to 40 dB gain – each of 16 channels0 to 40 dB gain – each of 16 channels –(2 spare IF to baseband converters) Controlled by RS232 serial portControlled by RS232 serial port Overflow/Saturation detectionOverflow/Saturation detection Remote Operation (Displays as well)Remote Operation (Displays as well)

GALFA Spectrometer

Multi-Purpose FPGA-Based Spectrometer (NSF, A. Parsons) Xilinx Virtex-II 6000 FPGA Xilinx Virtex-II 1000 FPGA 256 MB DRAM Arecibo Feed Array 200 Mhz ADC Compact PCI Backplane Software 200 Mhz ADC 200 Mhz ADC 200 Mhz ADC I I Q Q Pol. 1 Pol. 2 { { 200 Aux. I/O

compactPCI Power Power Cooling Cooling Robust/Reliable Robust/Reliable Inexpensive Inexpensive FPGA-Based Spectrometer

SETI Applications ALFA Sky Survey (300 MHz x 7 beams)ALFA Sky Survey (300 MHz x 7 beams) Parkes Southern SERENDIPParkes Southern SERENDIP JPL/UCB/SI Survey (20 GHz Bandwidth)JPL/UCB/SI Survey (20 GHz Bandwidth) SETI Italia (Bologna)SETI Italia (Bologna) Astronomy Applications GALFA Spectrometer – Arecibo Multibeam Hydrogen SurveyGALFA Spectrometer – Arecibo Multibeam Hydrogen Survey Astronomy Signal Processor – ASP – Backer/Stairs (pulsars)Astronomy Signal Processor – ASP – Backer/Stairs (pulsars) –GreenBank and Arecibo, soon Nancay ATA4 Correlator F EngineATA4 Correlator F Engine Two Reionization ExperimentsTwo Reionization Experiments (Backer/Demorest/Peeks (UCB), Chippendale/Green/Ekers (ATNF)) (Backer/Demorest/Peeks (UCB), Chippendale/Green/Ekers (ATNF))

GALFA Spectrometer sin cos LPF 100 MHz -50 to +50 MHz sin cos LPF 100 MHz -50 to +50 MHz Quadrature Downconverter Board IF Pol. 1 IF Pol. 2 Biplex 256 pnt. PFB e^-i  t FIR LPF FIR LPF Digital LO Decimate by 14 Decimate by 14 Biplex 8192 pnt. PFB     Detect cPCI Backplan e to CPU Multipurpose Spectrometer Board

PFB vs. FFT

GALFA Lowpass Filter

GALFA Diagnostics

Integration Time 988 mS fixed (99% duty cycle)988 mS fixed (99% duty cycle) Spectra read out every secondSpectra read out every second Integration starts 6 mS after 1 PPSIntegration starts 6 mS after 1 PPS Integration stops 6 mS before 1 PPSIntegration stops 6 mS before 1 PPS Timing accuracy +-10 nS wrt observatoryTiming accuracy +-10 nS wrt observatory

Data Output Galfa.yyyymmdd.projname.sequence_number.FITSGalfa.yyyymmdd.projname.sequence_number.FITS file written every 15 seconds (programmable)file written every 15 seconds (programmable) 0.5 Mbyte/sec (8 MByte files)0.5 Mbyte/sec (8 MByte files) Files written over NFS to file serverFiles written over NFS to file server 2*8K + 2* bit powers (42 bit accumulators)2*8K + 2* bit powers (42 bit accumulators) Time stamped (NTP), plus telescope dataTime stamped (NTP), plus telescope data

Worries, Weaknesses ADC on same board with Digital ElectronicsADC on same board with Digital Electronics (spurs at MHz…) (spurs at MHz…) Dynamic Range Problems (Overflow/Saturation)Dynamic Range Problems (Overflow/Saturation) (prog. gain/shifting, overflow detection) (prog. gain/shifting, overflow detection) Unknown LO phase shift (0 or 180 degrees) between channels after power cycleUnknown LO phase shift (0 or 180 degrees) between channels after power cycle – (LO is divided by two in downconverter)

Spectrometer Documentation Schematics, Cabling DiagramsSchematics, Cabling Diagrams Software (Source code)Software (Source code) Users ManualUsers Manual DiagnosticsDiagnostics About 100 Pages of stuffAbout 100 Pages of stuff

Short Term Plans Tonight: Jeff Mock ArrivesTonight: Jeff Mock Arrives Monday – Thursday: Integration/TestMonday – Thursday: Integration/Test Friday – Sunday: ObserveFriday – Sunday: Observe This week: come and visit for demoThis week: come and visit for demo feel, touch, and get to know your spectrometer feel, touch, and get to know your spectrometer

Long Term Plans Find ETFind ET

Future SETI Spectrometers

SERENDIP V Polyphase Filter Bank Server w/ EDT card GbE Switch PC Server w/ EDT card Server w/ EDT card Server w/ EDT card PC GbE Switch PC GbE Switch PC GbE Switch PC 100 MHz Pol. 1 Pol. 2 Astronomy Signal Processor – Don Backer

SERENDIP V Spectrometer

Biplex Pipelined FFT Example: 8 pnt. FFT -4 Z -2 Z Switch Delay by N Coefficient Multiply add sub Unity -2 Z Z add sub 2 nd Roots of Unity Z -0 Z add sub 4 th Roots of Unity -4 Z Pol. 1 Pol. 2 Time Domain Frequency Domain

JFFT FFT controls Any length transformAny length transform Input width and output widthInput width and output width twiddle coefficient widthtwiddle coefficient width 3 or 4 multiplier complex multiply3 or 4 multiplier complex multiply Specify downshift or programmable downshift (optional rounding)Specify downshift or programmable downshift (optional rounding) Decimate FFT optionDecimate FFT option Blockram / CLB memory threshold optionBlockram / CLB memory threshold option Overflow detectionOverflow detection

JFFT additional PFB controls Filter overlapFilter overlap Width of filter coefficientsWidth of filter coefficients Window function for filter (hamming, hann, etc.)Window function for filter (hamming, hann, etc.) Import filter coefficients for custom filter performanceImport filter coefficients for custom filter performance

Moore’s Law in FPGA world 100X More efficient than micro-processors! 3X improvement per year!

Next Generation Board BEE2 (2004/5) – Chen Chang 5 Xilinx XC2VP705 Xilinx XC2VP70 40 GB RAM (8 GB each chip, 13Gbit/sec/chip)40 GB RAM (8 GB each chip, 13Gbit/sec/chip) 18 10Gbit/sec infiniband ports18 10Gbit/sec infiniband ports 50 boards per rack, Tbit/sec infiniband switch50 boards per rack, Tbit/sec infiniband switch Applications:Applications: –1 GHz, 1 Gchannel spectrometer (single board) –Next Generation ATA backends (ata32 = 2 boards) –SKA imaging

B2 Module: board layout 5 compute elements on a board Up to 400 billion CMAC/s performance communication bandwidth: – –240 Gbps on- board 360 Gbps off-board

Global Interconnects Commercial Infiniband switch from Mellanox, Voltaire, etc. – –Packet switched, non- blocking – –24 ~ 144 ports (4X) per chassis – –480Gbps ~ 2.88Tbps full duplex constant cross section bandwidth – –<$400 per port

19” 48RU Rack CabinCapacity 40 compute nodes in 5 chassis (8U) per rack Up to 16 trillion CMac/s performance per rack 250 Watt AC/DC power supply to each blade 12.5 Kwatt total power

Unified Digital Processing Architecture Distributed per antenna spectral channel processing Multiple reconfigurable backend application processing Commercial packet switched interconnect Backend data pulling through remote DMA access

Happy Birthday Carl