User's Manual

TABLE OF CONTENTS
Page
Avoiding Underflow and Overflow .......................................................................... 4-16
Final Adjustments ............................ ....... .............. ........... .............. .......................... 4-17
Output Format ................ .............. ............ ....................................... ......... .............. ..... 4-17
Trigonometric
Calculation Examples ...... ...... .............. ............ .............. .................. ....... 4-17
FPTAN and FPREM .................................................................................................... 4-17
Cosine Uses Sine Code .............................................................................................. 4-18
APPENDIX A
MACHINE INSTRUCTION ENCODING AND DECODING
APPENDIX
B
COMPATIBILITY BETWEEN THE 80287 NPX AND THE 8087
APPENDIX C
IMPLEMENTING THE IEEE P754 STANDARD
Options Implemented in the 80287 ................................................................................ C-1
Areas of the Standard Implemented in Software ................... ~...................................... C-1
Additional Software to Meet the Standard .... .................. ....... ..... ................... ............... C-2
GLOSSARY OF 80287 AND FLOATING-POINT TERMINOLOGY
INDEX
Figures
Figure Title Page
1-1 Evolution and Performance of Numeric Processors .............................................. 1-1
1-2 '80287 NPX Block Diagram ...................................................................................... 1-7
1-3
80287 Register Set ........................... ....... .............. ..... ...... .............. ......................... 1-9
1-4
80287 Status Word ............ ..... ............... ......... ........ ..... ...... ...... ......... .......... ........ ....... 1-10
1-5 80287 Control Word Format ........ ...... ............ ..... ....... ....... ....................... ............... 1-12
1-6
80287 Tag Word Format .......................................................................................... 1-13
1-7
80287 Instruction and Data Pointer Image in Memory .......................................... 1-13
1-8
80287 Number System ............................................. , .............................................. 1-15
1-9 Data Formats .............................................................
: .............................................. 1-16
1-10 Projective versus Affine Closure . ..... ................ ........... ....... ......... ....... ........ ............. 1-20
1-11·
Arithmetic Example Using Infinity ............................................. : .... ; ......................... 1-37
2-1 FSAVE/FRSTOR Memory Layout ........................................................................... 2-18
2-2 FSTENV/FLDENV Memory Layout ........................
; .................................... ; ........... 2-19
2-3
Sample 80287 Constants ........................................................................................ 2-41
2-4 Status Word RECORD Definition ............................................................................ 2-42
2-5
Structure Definition ..................................................... ; ............. ~ ......................... ; ..... 2-42
2-6
Sample PL/M-286 Program .................................................................................... 2-44
2-7
Sample ASM286 Program ....................................................................................... 2-46
2-8
Instructions and Register Stack .............................................................................. 2-47
2-9 Synchronizing References to
Shared Data . ..................... ..... ..... ........... ........... ...... 2-50
2-10
Documenting Data Synchronization ........ ......... ......... ...... ...... ......... ........................ 2-51
2-11 Nonconcurrent FIST Instruction Code Macro ........................................................ 2-51
2-12 Error Synchronization Examples ............................................................................. 2-52
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