- <Phillip or Shobana> Washington University in St. Louis

Apr 26, 2004

Liquid Architecture

Agenda

– Motivation– Architecture– Results– Related work– Epilogue– Demo– Thank you!

Motivation

Architecture – LEON Controller

Design Approach

– Start with Leon Processor base• Supplies many of the components that will be

needed in the end system.– Soft-core processor– Memory controller– General I/O Drivers (for Liquid “Architecture Project”)– System/Processor Bus (AMBA)

– Develop and Integrate new features• Control SW• Modify Boot ROM• AMBA to SDRAM Controller Adapter• Control Packet routing (MP3 cpp as base)• Validation Environment (MP3 Testbench as base)

Design Data• New/Modified Entities

– LEON Controller • Control LEON access to memory / Start of program

execution

– LEON Boot ROM • modified to poll a given memory address at boot up

– LEON Memory Controller• modified to interface with FPX SDRAM

• External Memory Interfaces– 1 SRAM/SDRAM Interface

• Estimated Size– Number of LUTs: 12,277 (31%) – Number of Slices: 7900 (41%)– Number of BlockRAMs: 54 (33%)– Synthesis Frequence: 30 MHz

Control S/W Architecture

Java Emulator of the H/W

(for debugging)

Internet

Choose a LEON Config & upload the program to profile

Control Software

FPX

Interaction with LEON

Basic steps for “User” to interface with LEON/SRAM:

1. Wait for “READY” message

2. Load Program to SRAM

3. Send LEON “START” message

4. Wait for “DATA” message

5. Read results from SRAM

Control S/W web page

S/W Compilation Flow

• Uses LECCS Compiler System– GCC Based

• Test PROMs used LEON compile scripts• General compile system developed uses

DOS .bat compile script– Compile w/ GCC– Assemble w/ GAS– Link w/ LD– Convert to binary w/ OBJCOPY– Convert to IP w/ Forth program

Compile script

sparc-rtems-gcc test.c -S

sparc-rtems-as test.s -o test.o

sparc-rtems-ld test.o -Ttext 0x0 -Tdata 0x1000 -Tbss 0x2000

sparc-rtems-objcopy a.out -O binary a.bin

\gforth0.6.2\gforth tobin.fs > \class\leon2\input_ip.dat

Results

• Statistics for LEON cache hits and misses of a benchmark application– …

• Improvement in performance of that app resulting from dynamic reconfiguration …

References & Related Work

– The base Leon system http://www.gaisler.com/download.html

– Other projects that have used the Leon system

• http://www.gaisler.com/leon.html#leonlinks

EpilogueConclusion

Ongoing work

Acknowledgements• <Phillip/ Shobana>, Scott Friedman, Ben, Huakai Zhang, Dr.Cytron,

Dr.Lockwood, Dr.Chamberlain, Dr.Fritts• NSF

More info• http://www.arl.wustl.edu/arl/projects/fpx/projects/liquid_arch/index.ht

m

The Demo…