Jeff Brownscheidle Maureen Delaney Eric Fluhr Pat Mc

Jeff Brownscheidle, Maureen Delaney, Eric Fluhr, Pat Mc. Ilmoyle, Tien Tran – IBM Systems & Technology Group POWER™ Synthesis The transition from custom circuit design to large block synthesis in a high performance environment © 2013 IBM Corporation

Overview § VLSI Design: A Brief History of Recent Processor Design at IBM § Methodology Evolution: From Custom-driven to Synthesis-driven § A New Design Style: Large Block Synthesis (LBS) § Converting Custom Designs into LBS Designs § Advantages and Techniques of LBS 2

A POWER™ Retrospective 3

Mechanisms of Microprocessor Complexity POWER 4 POWER 7 180 nm technology; 412 mm 2 45 nm technology; 567 mm 2 Dual Core 8 -Core Single Threaded 4 -way Simultaneous Multi-Threading per core 8 Execution Units 12 Execution Units 2 Single-Precision Floating Point Units 4 Double-Precision Floating Point Units Decimal Floating Point Unit Vector Unit supporting VMX/Alti. Vec Shared L 2 cache; Off-Chip L 3 cache 4 Dedicated L 2 cache per core; On-Chip L 3 cache (e. DRAM)

The Conventional Approach: Less Synthesis, More Custom ISU Generation 1 Custom Synthesized 5 ISU Generation 2

Trending Towards Synthesized Designs ISU Generation 3 6 Synthesized Logic Percent of Unit

Design Type Spectrum ni ch Te n sig De 4) Embedded, Fully Routed Custom Components 3) Embedded, Un-Routed Custom Components w Ne Design Customization qu es 5) Custom Design 2) Latch, Local Clock Buffer Preplacement 1) VHDL structuring & parm customization 0) Random Logic Module (“Flat” Synthesis) Design Effort 7

A New Design Type—Large Block Synthesis (LBS) Sample Configurations Synthesized Random Logic 8 Design Example

The Power of LBS § “Structured” Flat Design § Flexibility & Incremental Customization § Scalability § Fast path to initial timing § Reduction in layout time 9

Design Merging Individual Designs 10 Merged LBS

Migrating a Design to LBS Custom 11 LBS

VHDL Structuring Latches 12 Latches

Summary § Large Block Synthesis: A modern, versatile alternative to custom highperformance design § Potential power and area savings over full custom design § Ability to iteratively increase custom designer input to converge toward a circuit solution § Long-term outlook: Can LBS radically influence future time-to-market expectations? 13