The New Layout Solution for Analog and Mixed

The New Layout Solution for Analog and Mixed Signal Design Oct 29, 2007 思源科技 產品二處 資深處長白錫鴻

IC 設計及製造流程 Idea Architecture Design Block Diagram Circuit & Layout Design Layout IC Fabrication Package& Testing System Manufacture 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 1 Wafer (Hundreds of dies)

晶片佈局圖(Layout)與實現方法 客製化線路 設計及佈局 Schematic Editor 數位邏輯設 計及佈局 Digital P&R Floor plan & Prototyping Placement & Route Analog module RTL Design & Synthesis SRAM AD/DAC 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 2 Simulation Console Laker. Wave Common Database Layout Editor

Today’s Industry Problems v Analog layout not automated Ø Mostly handcrafted – slow & error prone with complex rules Ø Prevent early parasitic extraction for simulation v Design time for a new analog block is large due to the lack of reuse scheme v Growing design complexity Ø 90 nm, 65 nm, and 45 nm § Complex design rule § Parasitic behavior complexity, thermal and process variations, and noise interactions Ø DFM constraints v Analog design productivity lags digital Ø Lack of a breakthrough on productivity of custom design Gates or Analog Transistors per Hour* Huge productivity gap 100, 000 1, 000 10 9/16/2020 Digital Flow: © 2004 SPRINGSOFT INC. Flow: Analog Schematic Synthesis SPICE Duplication, reuse or transfer of ownership requires advanced written authorization Integrated Flows PCells 3 *Sources: ITRI Next generation analog and mixed signal design forum 3 rd Party IP No Change Virtual Prototype No Change

Influence Factors on Layout Productivity & Quality v. Engineer experience v. Design difficulty ØEffective communication between designer and layout engineer v. Tools ØEasy of use ØPowerful features ØLayout Solution 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 4

Layout Solution -- Polygon Pushing v. Strength ØFlexibility ØOptimum layout result v. Issues ØWorst productivity ØProne to DRC/LVS error 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 5

Layout Solution -- SDL (Schematic-Driven) v Strength Ø Connectivity from design to minimize LVS error Ø Design topology awareness from schematic to minimize communication mistake Ø Better productivity than polygon pushing v Challenges Ø Powerful device model Ø Flexibility on design hierarchical management 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 6

Powerful Devices Model -- Magic Cell (1) Create Magic cell with different single gate multi-gate structure pattern Easy to Create Design Rule Correct Devices 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 7

Powerful Devices Model -- Magic Cell (2) Merge Gate Before Split Gate After Before Insert Gate Before Subduce Gate After Before 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization After 8 After

Vision on Design Driven Layout Flow Constraint Editor Schematic Entry Simulation Interface Designer Optional Constraint Partition Automatic Constraint Circuit Simulation Automatic Results Custom Layout Prototyping view Prototyping Simulation Post Layout 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization DRC/LVS Simulation 9 RC Extraction

Layout Solution -- DDL (Design-Driven) v. Strength ØExtract design constraints from design and simulation result ØUnify design and constraint DB to minimize design communication between designer and layout engineer ØConstraint driven custom device placement and wire routing 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 10

CMOS LAYOUT CASE STUDY-CIRCUIT 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 11

CMOS LAYOUT CASE STUDY >>OP 1 NW OD P+ N+ P 1 P 2 CO M 1 M 2 VIA 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 12

CMOS LAYOUT CASE STUDY >>OP 2 444 6 2 3 5 IP IN 3 5 1 4 6 7 8 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 13 7 8 NW OD P+ N+ P 1 P 2 CO M 1 M 2 VIA

Constraint Extraction (1/2) v. Extract Matching device constraints for MOSFETs v. Examples: 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 14

Constraint Extraction (2/2) v. Extract symmetry device constraints for MOSFETs v. Examples M 5 M 6 M 1 M 2 M 7 M 8 M 9 M 10 M 11 Self-Symmetry 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 15

Constraint Editor and Extractor v. Auto extract matching and symmetry constraints v. Manage and adjust constraints interactively 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 16

Matching Device Creator v. Routing style – backbone, cross route, … v. Comprehensive creation and editing capability 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 17

Matching Device Window - Preview v. Reduce create Placement iteration 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 18

Custom Placer – Transistor Based v. Honor Placement Constraints v. Support Incremental Placement 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 19

Layout Solutions For Custom Design Schematic-Driven Design-driven Schematic-driven Polygon-pushing Rule-Driven Rule-driven Polygon editing 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization Viewing 20

Summary on Layout Solution Quality • DRC Rule-driven • P 2 P Issues • Time Consuming • Error Prone Polygon Pushing • Powerful Devices Model • Hierarchical Manipulation • Constraint Extractor • Custom Placer & Router Issues • Prepare Parameterized cell • Lack of flexibility • Non-optimized Area Issues • Tedious constraint preparation • Inconsistent constraints between design and layout Schematic Driven 9/16/2020 © 2004 SPRINGSOFT INC. Duplication, reuse or transfer of ownership requires advanced written authorization 21 Design Driven Productivity