Logic Design for Array-Based Circuits

Copyright © 1996, 2001, 2002, 2008, 2016 Donnamaie E. White, WhitePubs Enterprises, Inc.

• Table of Contents
  
• Preface
  
• Overview
  
• Chapter 1 Introduction
  
• Chapter 2 Structured Design Methodology
• Chapter 3 Sizing the Design
• Chapter 3 Appendix = Case Study in Sizing a Design
• Chapter 4 Design Optimization
• Chapter 5 Timing Analysis for Arrays
• Chapter 6 External Set-up and Hold Times
• Chapter 7 Power Considerations
• Case Study: DC Power Computation
  • Steps Required to Compute DC Power - Example Array Series
  • Build the Macro Occurence Table
  • Find the Tital Interface Macro Current
  • Computer the Worst-Case Interface Current
  • Compute the Total Typical Internal Macro Current
  • Compute the Worst-Case Internal Current
  • Compute the Total Typical Overhead Current
  • Compute the Worst-Case Overhead Current
  • Sum the ICC and IEE Currents
  • Multiply by Worst-Case Voltage
  • Determine ECL Static Power PEO
  • ECL Output Termination Current
  • Sum the Result - Total DC Power
  • Exercises
• Case Study: AC Power Computation
  • Build the Macro Occurrence Table
  • Find the Number of Darlington Outputs
  • Compute AC Power for all ECL Darlington Output Macros
  • Find the Number of ECL Inputs
  • Compute AM Power for all ECL Input Macros
  • Find the Number of Internal Macros
  • Compute AC Power for all Internal Macros
  • Sum All Components of AC Power
  • Total Power Dissipation
  • Exercises
• Chapter 8 Simulation
• Case Study: Simulation
• Chapter 9 Faults and Fault Detection
• Chapter 10 Design Submission
• ASIC Glossary
  • Glossary A-D
  • Glossary E-K
  • Glossary L-R
  • Glossary S-Z
  • Symbols

Power Considerations

Last Edit July 22, 2001

Step 5: Compute AC Power For all ECL Input Macros

Using the counts from step 4, compute the AC power dissipated by the ECL inputs used in the circuit. For AMCC arrays, use:

PacI = f * n * 3.25 microwatts

where
f = frequency of operation in MHz
n = number of ECL input macros
conversion factor = 3.25 microwatt/macro-MHz for Q20000 Series

• Compute the AC power due to those input macros switching at the fastest frequency.
• Compute the AC power due to those macros switching at the next fastest frequency.
• Repeat until all ECL input macros are accounted for and sum the results.

Step 6: Find the Number of Internal Macros

Using the macro occurrence worksheet, find the number of internal macros. For AMCC customers, the number of internal macros can be determined from the AMCC Population ERC report.

Step 7: Compute AC Power For all Internal Macros

Using the count from step 6, estimate the AC power dissipated by the internal macros used in the circuit:

PacI = 0.20 * f * n * 3.25 microwatts

where
f = maximum frequency of operation in MHz
n = number of internal macros
0.2 = 20% switching
conversion factor = 3.25 microwatt/macro-MHz for Q20000 Series

Step 8: Sum All Components of AC Power

Sum the results together and convert to watts (or to the same units as was used for DC power). This equation provides an estimate of the worst-case AC power dissipation for the Q20000 array.

PdAC = PacI + Pacinternal + PacDARoutputs

Use the same equation for military and commercial computations.

Copyright © 1996, 2001, 2002, 2008, 2016 Donnamaie E. White , WhitePubs Enterprises, Inc.
For problems or questions on these pages, contact [email protected]