BEEKeeperRemote Management and Debugging of Large FPGA

Clusters

Terry Filiba

Navtej Sadhal

Background

• RAMP: Research Accelerator for Multiple Processors– Large array of Berkeley Emulation Engine (BEE2)

modules– Each BEE2 contains 5 Xilinx Virtex II Pro FPGAs

• 1 Master (control) FPGA• 4 Slave FPGAs

– 2 JTAG serial chains• Master can program slaves over 1 chain• Or slaves can be individually accessed over the other

Background

• CASPER: Center for Astronomy Signal Processing and Electronics Research– Processing is cheaper than building large

antennas– Instruments are remotely deployed at antenna

arrays– Using large arrays of BEE2 boards to develop

instruments for radio astronomy (currently correlators, beamformers, and spectrometers)

BEE2 Module

image from RAMP project: http://ramp.eecs.berkeley.edu/index.php?pictures

RAMP Blue

images from RAMP project: http://ramp.eecs.berkeley.edu/index.php?pictures

What is JTAG?

• Transports data serially throughout multiple chips– TMS : test mode– TCK : clock– TDI : test data in– TDO : test data out

image from Wikipedia: http://en.wikipedia.org/wiki/Image:Jtag_chain.svg

What is JTAG?

• Not very scalable– Each clock represents 1 bit of data moving through the system– In order to get test data into device 3 it has to go through device

1 and 2– Only suitable for a few chips daisy-chained together

image from Wikipedia: http://en.wikipedia.org/wiki/Image:Jtag_chain.svg

Background

• On-chip debugging with ChipScope– FPGA design can include debugging module

• Transmits debugging signal information over JTAG to host computer

– Host computer running ChipScope software receives data over parallel or USB cable

Problem

• We need to talk to individual FPGAs or boards to use ChipScope– Normal parallel or USB approach is limited

• Does not scale• Requires physical access to board

Proposed Solution

• Client driver– Intercepts ChipScope software

communications and transmits it over TCP/IP

• BEEKeeper– Mini-module with Xilinx Spartan 3 FPGA and

Ethernet port• MicroBlaze soft core runs C programs

– Receives data from host over TCP/IP and passes it on to BEE2 over JTAG

BEEKeeper Module

image from Avnet: http://www.em.avnet.com/img_shared/evk/df2df2usa/spartan3miniphoto.jpg

Proposed Solution

Proposed Solution

• User can change which BEE2 is being accessed by a local software switch

• Software can multiplex across many BEE2s to aggregate data

• User can remotely access BEE2s from anywhere with an Internet connection– Ideal for CASPER project

Implementation

Future Work

• Extend the client software to connect to multiple boards simultaneously– Program multiple FPGAs at once– Debug multiple FPGAs at once– Need a way to aggregate the data received

from the servers

• Integrate BEEKeeper hardware onto board to be debugged (BEE)

Questions?