CASPER Packetised correlators Jason Manley CASPER workshop 2009

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

CASPER DBE concept

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 Reformat DDCQuantize Channelize ADC Adding: Delay compensation Fringe rotation Later: Walsh switching

F engines 2010

X Engine Operations

Correlator Overview

How does it scale?

FPGA roadmap Processing power doubling every two years V4 = ½ power requirements of V2Pro* * Manufacturers claim - Xilinx Inc.

1 st 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. 1 st 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. 1 st 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 Manley