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
vii