Transcript A survey on Reconfigurable and Structure Adaptive

A survey on Reconfigurable Computing for
Signal Processing Applications
Anne Pratoomtong
Spring2002
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History of Reconfigurable
Computing
• FPGAs by Xilinx, 1986
Collection of fine grained programmable logic
blocks interconnected via wires and
programmable switches.
• Programmable digital signal processors (PDSP)
TMS32010 had a hardware multiplier and Harvard
architecture with separate on-chip bus for data
memory and program memory.
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Reconfigurable computing for
DSP
• Pre-Runtime Reconfigurable
• Run-time Reconfigurable (RTR)
-FPGAs base RTR
-Structure Adaptive RTR
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Pre-Runtime Reconfigurable
• Computing system or device logic
functionality and interconnect can be
customized to suit a specific application
through post-fabrication, user-defined
programming
• Hardware Platform contains a mix variety
of macro module with different
characteristic connected via reconfigurable
communication network
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Run-time Reconfigurable (RTR)
• System logic and/or interconnect
functionality can be modified during
application execution
• Useful for DSP applications whose
performance and functionality depend on
run-time factors such as time-varying noise,
runtime environment, computation
resources available, or time-varying data set
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FPGAs Base RTR
• The adaptation is done at the hardware level
using the FPGA base system.
• Develop methodology for fast and low
overhead reconfiguration.
• Software library or driver is developed to
handle reconfiguration request
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Structure Adaptive RTR : Self Adaptive Software
• Digital signal processing system can modify its
own structure (i.e. the composition of the signal
flow) while it is running.
• Software synthesis tool creates the executable
version of SFG.
• Run-time kernel schedules the computational
blocks as dictated by the control graph topology
and the availability of data and/or request. Each
computation blocks are consider as a process
which can run in UNIX-based, IBM-PC/DOS etc.
platform.
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Structure Adaptive RTR:Systemlevel synthesis
• Extend the capability of the Self-adaptive
software.
• Hardware platform is a part of system model and
is chosen by the designer.
• Construct system models of all possible aspect of
adaptive computing
• Perform synthesis based on the system models to
map the application into an execution platform
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Conclusion
• RTR system does not fully utilize the ability
to change the structure of the hardware
reconfigurable component such as FPGA
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Conclusion
• In some application, the need of RTR is
gone when implementation platform consist
of multiple computing hardware rather than
single computing hardware. The
performance factor for the 2 choices
depends on communication speed VS
reconfigurable overhead, area, and power
constraint. In general, the single hardware
implementation leads to a more power-area
effective system.
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Conclusion
Pre-Runtime
RTR
Adaptation
Change of
application
Change of run-time
environment
Flexibility
More general
Design toward
specific application
Complexity
Low
High
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Conclusion
• Hardware reconfiguration for the RTR
system largely occur during the synthesis
phase where the real time requirement does
not effect the performance. During the
runtime, the reconfiguration only occurs in
the form of changing the operating mode to
minimized the reconfiguration overhead.
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