1. Reconfigurable Hardware
Thomas Polzer

2. Overview Definition Methods Devices Applications Problems
Hardware or Software?

3. Definition Configurable Hardware Reconfigurable Hardware
Already seen in previous talk
A piece of hardware which can change its functionality according to a configuration.
Configuration only changed by developer
Reconfigurable Hardware
Special kind of configurable hardware
Configuration can be changed while device is operational

4. FPGA Layout
Source: [4]

5. Methods (I) Complete Reconfiguration Partial Reconfiguration
Whole configuration updated
Normally done by operator/developer
Device must be reinitialized
Partial Reconfiguration
Difference based
Module base

6. Methods (II) Difference Based Partial Reconfiguration
New and old configuration compared
Only changes are reprogrammed
Whole column reprogrammed

7. Methods (III) Module Based Partial Reconfiguration
Design partitioned into modules
Each module can be replaced in runtime
Other modules stay operational
Size and shape
Whole column
Rectangle
Special interfaces between modules

8. Methods (IV)
Source: [1]

9. Methods (V)
Controller
internal
external
Source:[2]

10. Devices (I) Xilinx Spartan-3 series Virtex series
Complete reconfiguration (only A and E series)
Difference based partial reconfiguration
Virtex series
Complete reconfiguration
Module based partial reconfiguration

11. Devices (II) Altera Atmel Stratix series Cyclone series
Complete reconfiguration
Cyclone series
Atmel
Field Programmable System Level Integrated Circuits (FPSLIC)
Module based partial reconfiguration

12. Devices (III) Lattice ORCA series Complete
Difference based partial reconfiguration
Module based partial reconfiguration

13. Applications (I) Increased Fault Tolerance Increased Capacity
Monitoring of functional units
In case of failure -> reconfigure empty space to replace it
Increased Capacity
Not all functional units deployed simultaneously
Remote Update
Download a new configuration via serial line or network

14. Applications (II) Speed-Up Reduction of power consumption
Special modules loaded on demand
Modules depending on task
Reduction of power consumption
Not all modules active
Inactive modules are not deployed
No power consumption by that modules

15. Problems Corrupted Configuration Data Security Safety
Possible solution: Fall back configuration
Security
Unauthorized changes to hardware
“Stealing” of the configuration
Safety
New layer of complexity
Harder to test
Harder to guarantee correctness
Unwanted reconfigurations

16. Hardware/Software Why it is Hardware Why it is Software
Still a system of logic gates
Inherent parallelism remains
Short execution time
Why it is Software
Has all the dynamic properties of software
Adaption to specific problems at runtime
Adaptive algorithms
Partly sequential operation
Easy to update

17. Thank you for your attention!
End
Thank you for your attention!

18. References 1 - Xilinx Application Note 290
2 - Hiibner, Schuck, Kiihnle, Becker - New 2-dimensional partial dynamic reconfiguration techniques for real-time adaptive microelectronic circuits - IEEE Computer Society Annual Symposium on Emerging VLSI Technologies and Architectures, 2006
3 – AT94S40AL datasheet
4 - Sedcole, Blodget, Becker, Anderson, Lysaght - Modular dynamic reconfiguration in Virtex FPGAs - IEEE Proc.-Comput. Digit. Tech., Vol. 153, No. 3, May 2006
5 - Emmert, Stroud, Skaggs - Dynamic Fault Tolerance in FPGAs via Partial Reconfiguration
6 - ORCA Series 3C and 3T FPGAs Data Sheet
7 – Amir H. Sheikh Zeineddini - Secure Partial Reconfiguration of FPGAs – Master Thesis