Using FPGAs with Embedded Processors for Complete Hardware and Software Systems Jonah Weber May 2, 2006

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems2 Overview Basics of embedded processors Design process Design examples Demo immediately following this talk

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems3 Types of Embedded Processors Hard Core –Embedded processor is a dedicated physical component of the chip, separate from the programmable logic –E.g. Xilinx Virtex families w/ PowerPC 405 Soft Core –Embedded processor is built out of the programmable logic on the chip –E.g. Xilinx MicroBlaze, Altera NIOS

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems4 Hard Core vs. Soft Core (Xilinx FPGAs) Hard CoreSoft Core

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems5 Hard Core vs. Soft Core Considerations Both cores utilize about the same % of total chip resources Hard core performance = 3-4x faster than fastest soft cores FPGAs with hard cores are more expensive Soft cores more flexible –Multiple cores can be used in a single chip –Can be used in a chip with a hard core

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems6 FPGA Embedded Processor Internal Bus Analog I/O I/F Dig I/O I/F External Memory I/F Ethernet I/F I/O Pins Custom Peripherals Standard Peripherals

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems7 Embedded Processor Internal Bus Analog I/O I/F Dig I/O I/F External Memory I/F Ethernet I/F Custom Peripherals Standard Peripherals I/O Pins Custom Board Ethernet Phy ADC DAC Digital I/O Analog I/O External Memory FPGA

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems8 Ethernet Phy ADC DAC Digital I/O Analog I/O External Memory FPGA Ethernet Network Instrument 1 Instrument 2 Instrument 3 I/O Custom Board System

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems9 Advantages of FPGA Embedded Processor Systems Merge CPU and I/O functions onto a single board Flexible design template – optimize power, data, and form factor to match application and I/O requirements Tightly coupled high speed logic and control system interface on a single chip – versatile tradeoff between hardware and software tasks Advanced tools bridge software and logic development, provide BSP generation for Linux, VxWorks

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems10 Design Process Step 1: Choose an evaluation board –Supported by development software –Closely matches I/O and peripheral requirements –There are at least 30 unique evaluation boards supported by Xilinx development tools! –Alternatively, select an FPGA Step 2: Construct printed-circuit board design based on evaluation board or FPGA Step 3: Create embedded design project

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems11 Xilinx Embedded Design Flow Base System Builder Configure Software Platform Create Custom Peripherals Populate and Connect Design Build Hardware Generate Complete Hardware/Software System Develop & Debug Software Applications Hardware DesignSoftware Design

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems12 Design Examples PEP-II TFB –Old system: 8 bit fixed delay on large power hungry boards –New system: 12-bit 2-tap programmable delay, extensive diagnostics ALS Bunch Cleaning –Zero crossing method increases excitation of parasite bunches, eliminates need for scrapers ALS Mini IOC –Booster ramp control for ALS top off operation –Flexible design for potential future applications

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems13 PEP-II TFB Started with Xilinx ML300 evaluation board set Used supplied CAD design files (PADS and DxDesigner) to modify design of ML300 CPU board Used ML300 Power I/O board as is Xilinx ML300 CPU Board PEP-II TFB CPU Board

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems14 ALS Bunch Cleaning Used Xilinx ML403 evaluation board as is Customized FPGA firmware Added external components: connectorized mixer and signal source

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems15 ALS Mini IOC Started with Avnet/Memec Mini Module Designed custom baseboard Use Mini Module as is Mini Module on evaluation base board ALS Mini IOC base board

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems16 Conclusion FPGAs with embedded processors can simplify design of instrument interfaces Starting with an evaluation board decreases development time Flexible physical implementation –Use evaluation board as is –Modify design files –Build custom design around selected FPGA

5/2/2006Using FPGAs with Embedded Processors for Complete Hardware and Software Systems17 Demo Avnet/Memec Mini Module evaluation board –FPGA = Xilinx Virtex-4 –Embedded Processor = PPC-405 hard core Mini Module is running EPICS on VxWorks with channels corresponding to LEDs and DIP switches on the base board Control and monitor the channels over Ethernet using Winprobe on a laptop