Hello Bob

1
Hello Bob An example application for the FPX

• Applied Research Laboratory
• Washington University, St. Louis
• http//www.arl.wustl.edu/arl/projects/fpx
• florian_at_arl.wustl.edu

2
Overview

• Full FPX application (incl. RAD)
• Parse UDP datagrams (using higher level
  framework)
• Send datagram back (UDP Echo)
• String match (Hello)
• Use SRAM interface (to read name)
• Replace data

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Replacing the content
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Simplified example

• Assume continuous data (easier for SRAM access)
• Limit name length to 14 characters (incl. \0)
• Name will fit in first cell
• Dont resize datagram (check for length)

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Hello Bob Tarball

• Download hellobob.tar.gz from
  http//www.arl.wustl.edu/arl/projects/fpx/workshop
  _0101/hellobob.tar.gz (save under D\)
• Unpack
• cd d
• tar xvzf hellobob.tar.gz
• Archive contains tree below FPX_TREE/RAD

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Compiling fpxlib

• Go to subdirectory HelloBob/MODULES/LIB
• Compile processors by typing make compile in
• CellProcessor/sim
• FrameProcessor/sim
• IPProcessor/sim
• UDPProcessor/sim

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Dataflow
HelloBob/MODULES/HelloBob/vhdl/hello_bob.vhdl
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Memory access

• Request memory when we receive frame
• Sample grant (and store it) before we access
  memory
• Save SRAM_GRANT on SOD
• If we dont get a grant use John Doe
• Release memory after processing name

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Statemachines
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HelloBob module
HelloBob/MODULES/HelloBob/vhdl/module.vhdl
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RAD core
HelloBob/TOP/RAD_HelloBob/vhdl/rad_hellobob.vhdl
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Testbench
HelloBob/TOP/RAD_HelloBob/sim/testbench.vhdl
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Compile Testbench

• Go to subdirectory HelloBob/TOP/RAD_HelloBob/sim
  
• Compile RAD and testbench by typing make compile

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Hello Bob

• Send control cell to write Bob to SRAM
• Is read from EGRESSIN.DAT
• Send UDP datagram with Hello..
• Is read from INGRESSIN.DAT
• Datagram with Hello Bob should return
• IP addresses and UDP ports should be swapped

15
Start simulator

• Go to subdirectory HelloBob/TOP/RAD_HelloBob/sim
  
• Type make sim (simulator starts up)
• Type do testbench.do (starts simulation)

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Exercises

• Implement Memory Statemachine
• Generate SRAM_REQ
• Sample SRAM_GRANT
• Replace payload with name
• Check terminating \0
• Watch for o_ and shift

HelloBob/MODULES/HelloBob/vhdl/hello_bob.vhdl
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Dataflow
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Testfiles

• PROBE.DAT probe-request
• SETVCI51.DAT control cell to change VCI from
  0x32 to 0x33
• SRAM_BOB.DAT write name Bob to SRAM
• UDP7HELLO.DAT datagram with Hello on port 7
• UDP7SALUT.DAT datagram with Salut on port 7
• UDP8HELLO.DAT datagram with Hello on port 8
• UDP51HELLO.DAT datagram with Hello on port 7,
  but VCI 0x33 (51)
• UDP0HELLO.DAT TTL field is zero

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Other tests

• Send Salut instead of Hello (UDP7SALUT.DAT)
• Type cp UDP7SALUT.DAT INGRESSIN.DAT
• Run test again
• Use port 8 instead of 7 (UDP8HELLO.DAT)
• NOTE testdata to HelloBob is read from
  INGRESSIN.DAT, testdata to the CCP is read from
  EGRESSIN.DAT

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Hello ltYour Namegt

• Login to jeeves (login on two terminals)
• User workshop
• ex workshop71 (port 7 stack 1)
• Password workshop
• Invoking fpx_control
• fpx_control fpx_number
• ex fpx_control 7.1
• Writing String
• enable rad logging g rad
• Write string ws mod_num address your name
• ex ws 1 0 Bob Smith

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Hello ltYour Namegt (cont)

• Open log_file in second terminal
• vi rad_log_xx.txt
• Copy cell to clipboard
• Highlight cell in vi
• Right click on xterm in toolbar
• Edit -gt Copy X Selection -gt To Clipboard
• Paste Selection in notepad
• Start -gt Run -gt notepad
• Edit -gt Paste
• Save file as EGRESSIN.DAT

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Different application VCI

• We will change the application VCI (0x32 to 0x33)
  by sending a control cell to the CellProcessor
• Create a new INGRESSIN.DAT from SETVCI51.DAT and
  UDP7HELLO.DAT
• Type cat SETVCI51.DAT UDP7HELLO.DAT gt
  INGRESSIN.DAT
• Use UDP packet on channel 0x33 (51)
  UDP51HELLO.DAT

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Probe Request

• Sending a Probe-Request to the CellProcessor
  results in a Generic CellProcessor Version 1.0
  response
• Use PROBE.DAT to send control cell

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Change Probe Response

• Change Probe Response in CellProcessor to Hello
  Bob Version 1.0

H e l l o B o b V e r s i o n 1 . 0
48 65 6c 6c 6f 20 42 6f 62 20 56 65 72 73 69 6f 6e 20 31 2e 30
HelloBob/MODULES/LIB/CellProcessor/vhdl/cellproc.v
hdl
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AAL5 Errors

• Change payload word, do not change the CRC
• CRC field is non-zero (error) in FrameProcessor

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TTL of zero

• IP packets with TTLzero are dropped
  (UDP0HELLO.DAT)
• Frame does not appear on data output