Intel 80287 User Manual

INSTRUCTION {
POINTER
OPERAND {
POINTER
PROGRAMMING NUMERIC APPLICATIONS
INCREASING ADDRESSES
15
15
CONTROL WORD CONTROL WORD
STATUS WORD
STATUS WORD
TAG WORD +4
TAG WORD
INSTRUCTION POINTER (15-0)
-6
IP OFFSET
CS SELECTOR
INSTRUCTION
;)1' I
INSTRUCTION
POINTER (19-16) 0
OPCODE (10-0)
-8
DATA POINTER (15-0)
·10 DATA OPERAND OFFSET
DATA POINTER I
(19-16)
0
.12
DATA OPERAND SELECTOR
TOPSTA
ELEMENT;
'"{
ST
s\
SIGNIFICAND 15-0
+14
SIGNIFICAND 31·16
+1.
SIGNIFICAND 47·32
+\8
SIGNIFICAND 63·48
+20
EXPONENT 14·0
+22
TOP STA
ELEMENT
'"{
:ST
5\
SIGNIFICAND 15-0
51GNIFICAND 31·16
SIGNIFICANO 47·32
SIGNIFICAND 63·48
EXPONENT 14-0
K NEXTSTAC
ELEMENT:ST(1
)
L
LAST STAC
ELEMENT:ST
Sl
SIGNIFICAND 15·0
+2'
SIGNIFICANO 31·16
+2.
51GNIFICAND 47·32
+28
SIGNIFICAND 63·48
+30
EXPONENT 14·0
+32
SIGNIFICAND 15·0
+84
SIGNIFICAND 31-16
+8.
SIGNIFfCAND 47·32
+88
SIGNIFICAND 63·48
+90
14-0
+92
REAL MODE
NOTES:
S = Sign
K NEXT STAC
ElEMENT:ST
(I)
L
'"{
T(7)
LAST STA
ELEMENT:S
5\
SIGNIFICAND 15-0
SIGNIFICAND 31·16
SIGNIFICAND
47·32
SIGNIFICAND 63·48
EXPONENT 14-0
SIGNIFICAND 15-0
SlGNIF1CAND 31·16
SIGNIFICAND
47·32
SIGNIFICAND 63·48
EXPONENT 14-0
PROTECTED MODE
Bit 0 01 each field is rightmost. least slgnilicant bit of corresponding
register field.
Bit 63 of signiflcand is integer bit (assumed binary point is Immediately
to the righl).
Figure 2-1. FSAVE/FRSTOR Memory Layout
2-18
INCREASING ADDRESSES
. 1
-0
+4
+6
+8
+10
+12
+14
+1.
+18
+20
+22
+"
+2.
+28
+30
+32
+8'
+8.
+88
+90
+92
G30108
pcjs.org

Intel 80287 Specifications

General

Brand	Intel
Model	80287
Category	Computer Hardware
Language	English