a ADSP-2126x SHARC ® DSP Core Manual Revision 2.0, February 2004 Part Number 82-001999-01 Analog Devices, Inc. One Technology Way Norwood, Mass. 02062-9106 Copyright Information © 2004 Analog Devices, Inc., ALL RIGHTS RESERVED. This docu- ment may not be reproduced in an y form without prior , express written consent from Analog Devices, Inc. Printed in the USA. Disclaimer Analog Devices, Inc. reserves the right to change this product without prior notice. Information furnished by Analog Devices is believed to be accurate and reliable. However, no re sponsibility is assumed by Analog Devices for its use; nor for any infrin gement of patents or other rights of third parties which may result from its us e. No license is granted by impli- cation or otherwise under the pate nt rights of Analog Devices, Inc. Trademark and Service Mark Notice The Analog Devices logo, SHARC, the SHARC logo and VisualDSP++ are registered trademarks of Analog Devices, Inc. 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ADSP-2126x SHARC DSP Core Manual iii CONTENTS PREFACE Purpose of This Manual ................................................................ xvii Intended Audience ........................................................................ xvii Manual Contents ......................................................................... xviii Additional Literature ...................................................................... xix What’s New in This Manual ............................................................ xx Technical or Customer Support ....................................................... xx Processor Family ............................................................................. xx Product Information ...................................................................... xxi DSP Product Information ......................................................... xxi Product Related Documents .................................................... xxii Technical Publications Online or on the Web ........................... xxii Printed Manuals .................................................................... xxiii VisualDSP++ and Tools Manuals ....................................... xxiii Hardware Manuals ............................................................ xxiii Data Sheets ....................................................................... xxiii Recommendations for Improving our Documents ................... xxiv Conventions ................................................................................ xxiv iv ADSP-2126x SHARC DSP Core Manual INTRODUCTION Overview—Why Floating-P oint DSP? ........................................... 1-1 ADSP-2126x DSP Design Ad vantages ........................................... 1-1 Architectural Overview ................................................................. 1-5 Processor Core ........................................................................ 1-5 Processing Elements ............................................................ 1-6 Program Sequence Control ................................................. 1-7 Processor Internal Buses ...................................................... 1-9 Processor Peripherals ............................................................. 1-10 Dual-Ported Internal Memory (SRAM) ............................. 1-11 Timers ............................................................................. 1-12 JTAG Port ........................................................................ 1-12 Development Tools ..................................................................... 1-13 Differences From Previous SHARC DSPs .................................... 1-13 Processor Core Enhancements ............................................... 1-13 Processor Internal Bus Enhancements .................................... 1-14 Memory Organization Enhancements .................................... 1-15 JTAG Port Enhancements ..................................................... 1-15 Instruction Set Enhancements ............................................... 1-15 PROCESSING ELEMENTS Numeric Formats .......................................................................... 2-2 IEEE Single-Precision Floating-Point Data Format ................... 2-2 Extended-Precision Floating-Point Format ............................... 2-5 ADSP-2126x SHARC DSP Core Manual v Short Word Floating-Point Format ........................................... 2-5 Packing for Floating-P oint Data ............................................... 2-6 Fixed-Point Formats ................................................................ 2-8 Setting Computational Modes ..................................................... 2-11 32-Bit Floating-Point Format (Normal Word) ........................ 2-11 40-Bit Floating-Point Format ................................................. 2-13 16-Bit Floating-Point Format (Short Word) ........................... 2-13 32-Bit Fixed-Point Format ..................................................... 2-14 Rounding Mode .................................................................... 2-14 Using Computational Status ........................................................ 2-15 Arithmetic Logic Unit (ALU) ...................................................... 2-16 ALU Operation ..................................................................... 2-16 ALU Saturation ..................................................................... 2-17 ALU Status Flags ................................................................... 2-18 ALU Instruction Summary .................................................... 2-19 Multiply Accumulator (Multiplier) .............................................. 2-22 Multiplier Operation ............................................................. 2-23 Multiplier Result Register (Fixed-Point) ................................. 2-23 Multiplier Status Flags ........................................................... 2-26 Multiplier Instruction Summary ............................................ 2-27 Barrel Shifter (Shifter) ................................................................. 2-30 Shifter Operation .................................................................. 2-30 Shifter Status Flags ................................................................ 2-33 Shifter Instruction Summary .................................................. 2-35