The FPX KCPSM Module: An Embedded, Reconfigurable Active Processing Module for the FPX

1. The FPX KCPSM Module:An Embedded, Reconfigurable Active Processing Module for the FPX Henry Fu Washington University Applied Research Lab Supported by: NSF ANI-0096052 and Xilinx Corp. http://www.arl.wustl.edu/arl/projects/fpx/fpx_kcpsm/ hwf1@arl.wustl.edu

2. Motivation • Hardware plugins are well suited for processing data with high throughput • Software plugins are well suited for implementing complex control functions • Need a hybrid plugins that can implement complex control functions with high data throughput

3. Introduction • The FPX KCPSM module is a hardware plugin that executes software on an embedded soft-core processor • It implements active networking functions on the FPX using both hardware and software • It includes circuits to be reprogrammed over the network and to execute new programs between the processing of data packets

4. Overview • The FPX KCPSM Module is composed of three parts: • The KCPSM, a 8-bit microprocessor developed by Xilinx Corp. • The Protocol Wrappers, a circuit used to simplify the processing of ATM cells, AAL5 frames, IP packets, and UDP datagrams • The Interface, a circuit used to interconnect the KCPSM and the Protocol Wrappers

5. The FPX KCPSM Module KCPSM PORT_ID I/O ADDR INST BUS DATA PROGRAM UDP PACKETS UDP PACKETS ATM CELLS ATM CELLS MEMORY MEMORY ADDR DATA ADDR INST BUS D_MOD_IN D_OUT_MOD D_MOD_IN D_OUT_MOD INTERFACE SOC_MOD_IN SOC_OUT_MOD TCA_MOD_IN CONTROL CONTROL TCA_OUT_MOD SIGNALS SIGNALS PROTOCOL WRAPPERS CLK RESET_L ENABLE_L READY_L

6. Features • Software can be loaded over the network through the use of UDP datagrams • Up to four data packets and up to two programs can be stored in the module at a time • The processing function can be changed dynamically, on a packet by packet basis

7. Background of the FPX • The FPX (Field Programmable Port Extender) • A reprogrammable logic device that provides a hardware platform to deploy network modules • It is composed of two parts: • NID (Network Interface Device), a circuit that interconnects the WUGS (Washington University Gigabit Switch), the line cards, and the RAD • RAD (Reprogrammable Application Device), a circuit that can be reprogrammed to hold user-defined network modules

8. Configuration of the FPX • The FPX acts as an interface between the line cards and the WUGS FPX Line Card IPP OPP Field- OC3/ programmable IPP OPP OC12/ Port OC48 Extender Gigabit Switch Fabric FPX Line IPP OPP Card Field- IPP OPP OC3/ programmable OC12/ Port OC48 Extender

9. Major Components of the FPX Data Data SDRAM SDRAM Module Module Data Data SRAM SRAM RAD VC VC RAD Program SRAM NID VC VC FPX EC EC Switch LineCard Loopback KCPSM

10. Background of the KCPSM • The KCPSM (Constant (K) Coded Programmable State Machine) • A 8-bit microcontroller • Consumes only 35 CLBs in FPGA • Provides 49 different instructions, 16 registers, 256 directly and indirectly addressable ports, and a maskable interrupt • Runs at a maximum frequency of 70 MHz • Developed by Ken Chapman of Xilinx Corp.

11. Background of the KCPSM (More) INPUT [7:0] OUTPUT [7:0] INTERRUPT PORT_ID [7:0] KCPSM READ_STROBE WRITE_STROBE CLK INST [15:0] ADDR [7:0] • The KCPSM • Designed for Xilinx Virtex and Spart-II devices • Provided in the form of an EDIF macro • Included an assembler and debugger

12. Downloading the KCPSM Package • The KCPSM Package from Xilinx Corp. • Visit • http://www.arl.wustl.edu/arl/projects/fpx/fpx_kcpsm • Left click on the KCPSM package • Open the ZIP file • Extract to h:\xilinx • Start Cygwin Bash Shell • Engineering > FPGA Tools > Cygwin Bash Shell • cd /cygdrive/h/xilinx/

13. Contents of the KCPSM Package • Access the KCPSM Package • An assembler called KCPSMBLE • ./KCPSMBLE debug.psm • An debugger called PSMDEBUG • ./PSMDEBUG debug.coe • Documentations • A modified KCPSM package that includes example programs will be included as part of the FPX KCPSM package during the exercise

14. Background of the Protocol Wrappers • The Protocol Wrappers • A circuit that streamline the networking functions to process ATM cells, AAL5 frames, IP packets, and UDP datagrams • A layered design that consists different processing circuit in each layer • Allows application to be implemented at a level where important details are exposed and irrelevant details are hidden

15. Overview of the Protocol Wrappers • The Protocol Wrappers is composed of four circuits: • Cell Processor processes raw ATM cells between network interfaces • Frame Processor processes variable length AAL5 frames • IP Processor processes IP packets • UDP Processor sends and receives UDP datagrams

16. Overview of the Protocol Wrappers (More) UDP Processor IP Processor Frame Processor Cell Processor Interfaces to Off-Chip Memories Application-level Hardware Module Data Input Data Output

17. Downloading the Wrappers Package • The Protocol Wrappers Package • Visit • http://www.arl.wustl.edu/arl/projects/fpx/fpx_kcpsm • Right click on the Wrappers Package • Save it to h:\ • Start Cygwin Bash Shell • Engineering > FPGA Tools > Cygwin Bash Shell • cd /cygdrive/h/ • gunzip wrappers.tar.gz • tar xvf wrappers.tar

18. Contents of the Protocol Wrappers Package • Access the Protocol Wrappers Package • Cell Processor • cellwrapper.vhdl, the VHDL instantiation file • cellproc_sim.vhd, the VHDL simulation file • cellproc.edn, the EDIF Macro synthesis file • Frame Processor • framewrapper.vhdl, the VHDL instantiation file • frameproc_sim.vhd, the VHDL simulation file • frameproc.edn, the EDIF Macro synthesis file

19. Contents of the Protocol Wrappers Package • IP Processor • ipwrapper.vhdl, the VHDL instantiation file • ipproc_sim.vhd, the VHDL simulation file • ipproc.edn, the EDIF Macro synthesis file • UDP Processor • udpwrapper.vhdl, the VHDL instantiation file • udpproc_sim.vhd, the VHDL simulation file • udpproc.edn, the EDIF Macro synthesis file • COREGEN Components

20. Overview of the Interface • The Interface • A circuit that interconnects the KCPSM and the Protocol Wrappers • Switches the source and destination IP address and UDP port numbers, buffers the incoming UDP packets and stores them to the memory, resets the KCPSM, and writes the outgoing UDP packets back to the sender

21. Overview of the Interface (More) • The Interface is composed of seven control units: • UDP Packets Header Switch • UDP Packets FIFO Control • UDP Packets Type Check • UDP Packets Store Control • KCPSM Reset Control • Unmodified Program Packets Echo Control • Completed Data Packets Write Control

22. Overview of the Interface (More) KCPSM Control Control Signals Signals ADDR INST ADDR DATA KCPSM Program Data Reset Control Memory Memory Completed Data Packet UDP Packets Program Data Data Packets Packet Packet FIFO Control Write Control UDP Control Buffered Write Packet Signals UDP Grant Packet UDP Packets UDP Packets FIFO UDP UDP Header Switch Store Control Packet Packet Unmodified UDP Control Program Packet Signals Packet UDP Packets Program Pkts Type Check Echo Control

23. Overview of the Interface (More) KCPSM Control Control Signals Signals ADDR INST ADDR DATA KCPSM Program Data Reset Control Memory Memory Completed Data Packet UDP Packets Program Data Data Packets Packet Packet FIFO Control Write Control UDP Control Buffered Write Packet Signals UDP Grant Packet UDP Packets UDP Packets FIFO UDP UDP Header Switch Store Control Packet Packet Unmodified UDP Control Program Packet Signals Packet UDP Packets Program Pkts Type Check Echo Control

24. UDP Packets Header Switch Control • UDP Packets Header Switch Control • Switches the source and destination IP address and UDP Port numbers of the UDP packets • Allows the unmodified program packets and completed data packets to be echoed back to the sender

25. UDP Packets FIFO Control • UDP Packets FIFO Control • Buffers incoming UDP packets • Delays the arrival of the UDP packets to the UDP Packets Store Control so that it can wait for the result from the UDP Packet Type Check in order to determine whether to store the UDP packets into the program memory or into the data memory

26. UDP Packets Type Check • UDP Packets Type Check • Determines if the incoming UDP packets is a program packet or a data packet • Inspects the first word of the UDP payload • 0x00000000 indicates a program packet • 0x00000001 indicates a data packet

27. UDP Packets Store Control • UDP Packets Store Control • If the incoming packet is a program packet • Stores the UDP payload, except the first word, into the program memory • If the incoming packet is a data packet • Stores the whole packets, including the ATM, AAL5 Frame, IP and UDP headers, the UDP payload, and the ATM trailers into the data memory • Increments the bank counters so that the next UDP packet will store into the next available bank of memory

28. KCPSM Reset Control • KCPSM Reset Control • Resets the KCPSM by asserting the Interrupt input of the KCPSM for two clock cycles • If there is no new program loaded • Resets the KCPSM so that it processes the next available data packets using the current program • If there is a new program loaded • Resets the KCPSM and increments the program counter so that it processes the next available data packets using the new program

29. Unmodified Program Packets Echo Control • Unmodified Program Packets Echo Control • Echoes the incoming program packets back to the sender • Passes any non-UDP packets through the module

30. Completed Data Packets Write Control • Completed Data Packets Write Control • Writes the completed data packets back to the sender only if • they have been processed by the KCPSM • there is no new incoming data packet by inspecting the WR_GRANT signal from the UDP Packets Store Control

31. The FPX KCPSM Module Demo • Network Data Compression using RLE (Run-Length Encoding) Algorithm • Compression example: • ‘AAAABBBC’ compresses to ‘A4B3C’ • Decompression example: • ‘A4B3C’ decompresses to ‘AAAABBBC’ • Allowed input characters range from ‘A’ to ‘Z’, ‘a’ to ‘z’

32. The FPX KCPSM Module Demo (More) • Log on to fpx.arl.wustl.edu / fpx2.arl.wustl.edu using SSH (Secure Shell) • fpx / fpx2 is connected to the line cards / fpx boards / WUGS • fpx / fpx2 directs network traffic to the line cards / fpx boards / WUGS • IP over ATM is configured on fpx / fpx2 to send UDP packets on VCI / VPI #96

33. The FPX KCPSM Module Demo (More) • A C program called UDPTEST is executed on the fpx / fpx2 and is used to send program packets to the FPX KCPSM module • Download URL: • http://www.arl.wustl.edu/arl/projects/fpx/fpx_kcpsm/ • Usage: • ./UDPTEST RLEEN.TBP (Encoder) • ./UDPTEST RLEDE.TBP (Decoder) • The <FILENAME.TBP> file contains the raw machine code of the KCPSM program

34. Program Packet Processing Independent KCPSM Process ADDR INST ALTERNATE CURRENT BANK BANK PROGRAM MEMORY Proceed as long as Proceed as long as there is new incoming there is new incoming program packet ADDR INST program packet INTERFACE Program Packet Program Packet

35. The FPX KCPSM Module Demo (More) • A C program called UDPSTR is executed on the fpx / fpx2 and is used to send data packets containing character strings to the FPX KCPSM module • Download URL: • http://www.arl.wustl.edu/arl/projects/fpx/fpx_kcpsm/ • Usage: • ./UDPSTR [-h hostname] [-p destination port] • Enter the character strings in the input prompt

36. Data Packet Processing Proceed as long as KCPSM there is data packet ADDR I/O BUS ALT ALT ALT CUR BANK BANK BANK BANK DA TA MEM ORY Proceed as long as Proceed as long as there is new there is completed data packet ADDR DATA ADDR DATA incoming data packet and no new incoming data packet BUS BUS INTERFACE Data Packet Data Packet

37. The FPX KCPSM Module (Demo) • Screenshot of the compression example:

38. The FPX KCPSM Module Demo (More) • Screenshot of the decompression example:

39. Synthesis Results • The FPX KCPSM Module is synthesized to a Xilinx XCV1000E-7-FG680: • Maximum Frequency: 70 MHz • Chip Utilization: 35% (4305 / 12288 slices) • External Input Buffers: 69 uses • External Output Buffers: 105 uses • Total LUTS: 3807 uses

40. Synthesis Results (More) • The Xinlinx backend synthesis script: • ngdbuild -p xcv1000e-7-fg680 -uc design.ucf • map -p xcv1000e-7-fg680 -o top.ncd design.ngd design.pcf • par -w -ol 2 top.ncd design.ncd design.pcf • trce design.ncd design.pcf -e 3 -o design.twr -xml design_trce.xml • bitgen design.ncd -b -l -w -f bitgen.ut

41. Conclusion • The FPX KCPSM Module • Demonstrates how to embed a softcore processor and how to use the Protocol Wrappers in an FPX module • Combines software flexibility and hardware performance into a hybrid module • Targets to work with the KCPSM, WUGS, FPX research environment, but can easily be changed to work with any FPGA-based system