Speaker
Mr
Karl Judex
(Industry)
Description
The bistatic Wind-LIDAR-System developed by German Physikalische-Technische Bundesanstalt (PTB) is a great practical example on how MicroTCA systems can solve computational challenges:
With 4 analog channels, each sampled at 350M samples per second with 16 bits per sample, 2800 MB/s of streaming data can be tackled with heterogeneous compute elements.
As a first-stage data processing instance we selected an FPGA, a Xilinx Virtex-7 690T with
multiple high-speed SerDes interfaces. The targeted measuring principle requires a deterministic
latency between the generated waveforms sent to the DACs and the corresponding input data. This
is guaranteed by using the JESD204B protocol to transfer the data between the FPGA and the
ADC/DAC. Our presentation will elaborate on the design choices and observations when using
JESD204B within an FPGA environment. The FPGA has the task to essentially reduce the data rate
and to transport the data to the DSPs, TMS320C6678 from TI, for subsequent data analysis. In our
presentation we will highlight the custom signal processing implemented inside the FPGA which
effectively reduces the data rate down to 50M samples per second with 32 bits per sample, per
channel.
Data transmission from the FPGA to the multi-DSP subcomponent is done via PCIe Gen3 x4 at
200MB/s per channel. We will demonstrate how we used a MicroTCA backplane for PCIe and go
into details of a custom protocol on top of PCIe which mimics the queue aspects of modern NVMe
SSDs to reduce latency and implementation effort. We will then discuss the architecture of three
separate DSP, two DSP for further processing per channel followed by overall processing done in
the third DSP, again reducing the amount of data. The DSP themselves are interconnected via PCIe
Gen2 x2, the third DSP also connects via Gigabit Ethernet on the MicroTCA backplane to transport
data at the final rate of 20MB/s to a PC component featuring an Intel i7 CPU. Finally, Ethernet on
the MicroTCA backplane is used for system-wide setup and control.
Primary author
Mr
Karl Judex
(Industry)
Co-authors
Mr
Joachim Förster
(Missing Link Electronics)
Dr
Michael Eggert
(Physikalisch-Technische Bundesanstalt)
Mr
Thomas Decker
(Missing Link Electronics)
