casper packetised correlators

CASPER Packetised correlators

Jason ManleyCASPER workshop 2009

Contents

• Dataflow• Engine operations• Present and future features• Scalability• Mapping to hardware• Present and future deployments

CASPER DBE concept

CASPER DBE concept

Making full use of 10GbE ports

Making full use of 10GbE ports

Clocking

• Clocks:

• Sampling synchronized at F engines, but clock not distributed to X

engines.

• X engines each run off independent local clock

• Synchronized using global 1pps signal at ADCs

• Propagated to X engines using out-of-band signaling on XAUI links

• Headers labeling 10GbE Ethernet packet data

F Engine Operations

ReformatDDC QuantizeChannelizeX Engine

ADC

• Adding:• Delay compensation• Fringe rotation

• Later:• Walsh switching

F engines 2010

X Engine Operations

Correlator Overview

How does it scale?

16 pol, 2k ch, 200MHz

64 pol, 2k ch, 200MHz

256 pol, 16k ch, 512MHz

1024 pol, 16k ch, 1GHz

4096 pol, 2M ch, 1GHz

8192 pol, 2M ch, 1GHz

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F EnginesX Engines

FPGA roadmap

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Xilinx Virtex Family

• Processing power doubling every two years• V4 = ½ power requirements of V2Pro*

* Manufacturers claim - Xilinx Inc.

1st generation: IBOB & BEE2

• IBOB F-engine, BEE2 X-engine.

• Development stopped at 32 antennas, 200MHz.

• Limited by single X engine length.

• Could split across multiple FPGAs, but elect to move to ROACH instead.

Generation 1.5: IBOB & ROACH• Currently up to 64 antennas.• Using existing IBOB F-engine, with ROACH X-engine.• Initial PAPER-SA deployment

Generation 2: Pure ROACH• Expect completion towards end of 2009• Anticipate designs up to 128 antennas• And bandwidths of 125MHz to 500MHz.• KAT-7, GMRT, ...

Next generation: ROACH-II• MeerKAT• Over 1GHz bandwidth, more than 256 antennas• Uses Xilinx 11 tools.

Existing systems: PAPER - Green Bank

• 8 dual-pol antennas, 150MHz.• 1st Generation: one BEE2 & four IBOBs.• First deployment of packetized system.• Continuous upgrades.

Existing systems: Northern Cross, Medicina, Italy

• Designed and deployed in under 2 weeks.• 32 single-pol antennas, 32 MHz.• 1st Generation:

• one BEE2• eight IBOBs.

New deployments: KAT-7• 7 dual-pol antennas, 400MHz.• Pure ROACH.• New control and monitoring interface (KATCP), coarse

delay, high speed output (less than 100ms).• Expected early 2010.

New deployments: GMRT• 32 dual-pol inputs, 400MHz bandwidth.• Collaboration – shares design with KAT-7.

New deployments: PSA-32/64/128• PAPER in South Africa, staged deployment• Up to 256 antennas, 100MHz • Generation 1.5 (IBOB+ROACH) initially,• Generation 2.5 (ROACH + ROACH-II) eventually.• First field deployment of ROACH system.• Deployment starting next week!

Jason Manleyjason_manley@hotmail.com