1. Trevor Burton6/19/2015 Multiprocessors for DSP SYSC5603 Digital Signal Processing Microprocessors, Software and Applications

2. Trevor Burton6/19/2015 Outline  Why Multiprocessor Systems?  Chip Multiprocessor (CMP) Architectures  CMP Advantages & Disadvantages  Current CMP Solutions  Tools for Designing and Simulation CMPs  Summary

3. Trevor Burton6/19/2015 Why Multiprocessor Systems?  Single-core microprocessor performance increases are beginning to slow [1] due to:  Increasing power consumption (>100 W)  Increasing heat dissipation  Diminishing performance gains from ILP & TLP [2]  As a result manufactures are turning to a multi-core microprocessor approach  Multiple smaller energy efficient processing cores are integrated onto a single chip  Improves overall performance by performing more work concurrently

4. Trevor Burton6/19/2015 CMP Architectures  Two general types of multi-core or chip multiprocessor (CMP) architectures  Homogeneous CMPs – all processing elements (PEs) are the same  Heterogeneous CMPs – comprised of different PEs  Homogenous dual-core processors for PCs are now available from all major manufactures  Heterogeneous CMPs are available in the form of multiprocessor systems-on-chips (MPSoCs)

5. Trevor Burton6/19/2015 Homogenous CMP - Quad-SHARC DSP [3] Core ADSP-21060 SHARC Functional Diagram Quad-SHARC Functional Diagram [3]

6. Trevor Burton6/19/2015 Heterogeneous CMP – Cell BE Cell Broadband Engine Block Diagram [4]

7. Trevor Burton6/19/2015 CMP Advantages  CMPs have several advantages over single processor solutions  Energy and silicon area efficiency By Incorporating smaller less complex cores onto a single chip Dynamically switching between cores and powering down unused cores [5]  Increased throughput performance by exploiting parallelism Multiple computing resources can take better advantage of instruction, thread, and process level parallelism

8. Trevor Burton6/19/2015 CMP Disadvantages  Poorer performance in single task situations  Need to have software that can be decomposed into multiple threads in order to take full advantage of CMP resources  Programming CMPs is inherently more difficult due to:  Software needing to be designed with multiple threads  Parallel programming and its associated issues such as shared memory access and message passing  Large number of possibly different types of PEs

9. Trevor Burton6/19/2015 Current CMP Solutions  Many different types of CMP solutions exist today and choosing one depends on the intended application  In the desktop computing industry all major manufactures now offer multi-core solutions  Manufactures of PDSPs also offer multi-core versions of their products  FPGA manufactures offer programmable devices with immersed microprocessor cores

10. Trevor Burton6/19/2015 Design and Simulation Tools  Of the multi-core solutions that exist none offer support for a multi-core design from scratch  Instead customers decide on a multi-core platform from a specific vendor and generally use the tools available from that vendor to program, test, and verify their multi-core solution  One solution for the design and simulation of multi- processor systems from the ground up is offered by Cmpware Inc.  They offer a configurable multi-processor development kit (CMP-DK) which allows for the design, programming, and testing of multi-processor systems

11. Trevor Burton6/19/2015 Design and Simulation Tools – The CMP-DK  Their development environment lets processors and their interconnection network be quickly and simply defined [6]  Existing processor cores along with their associated tools, libraries, and software can be used [6]  Also, users are able to specify their own custom processor architectures and interconnect networks or modify an existing architecture as needed.

12. Trevor Burton6/19/2015 Summary  The CMP architecture is now the architecture of choice for semiconductor manufactures  CMPs are more area and energy efficient than single processor solutions  CMPs achieve greater throughput than single processor solutions as more work can be done concurrently  Custom multi-processor systems can now be designed and simulated from the ground up using software solutions from several companies

13. Trevor Burton6/19/2015 References [1]D. Geer, “Chip makers turn to multicore processors,” IEEE Computer, vol. 38, no. 5, pp. 11-13, 2005. [2]L. Hammond, B. Hubbert, M. Siu, M. Prabhu, M. Chen and K. Olukotun, “The Stanford Hydra CMP”, IEEE Micro, vol. 20, no. 2, pp. 71-84, Mar./Apr. 2000. [3]AD14060 Data Sheets. (2004). Analog Devices. Norwood, MA. [Online]. Available: http://www.analog.com/UploadedFiles/Data_Sheets/ 4003696AD14060_L_b.pdf [4]Cell Broadband Engine Architecture and its first implementation. [Online]. Available: http://www- 128.ibm.com/developerworks/power/library/pa- cellperf/#23ref1

14. Trevor Burton6/19/2015 References [5]R. Kumar, D. M. Tullsen, N.P. Jouppi, and P. Ranganathan, “Heterogeneous Chip Multiprocessors,” IEEE Computer, vol. 38, no. 11, pp. 32-38, 2005. [6]S. A. Guccione. (2005, April). Programming Configurable Multiprocessors. Presented at the 12th Reconfigurable Architectures Workshop. [Online]. Available: http://www.cmpware.com/Papers/RAW2005/Cmpwar e_RAW_2005.pdf