PROGRAMMING NUMERIC APPLICATIONS

 

 

 

 

 

 

INCREASING ADDRESSES

 

 

 

 

 

 

15

CONTROL WORD

~ 15

 

CONTROL WORD

 

 

 

 

STATUS WORD

 

 

 

 

 

STATUS WORD

 

 

 

 

TAG WORD

 

+4

 

 

 

 

TAG WORD

 

 

INSTRUCTION POINTER (15-0)

 

-6

 

 

 

 

IP OFFSET

INSTRUCTION {

 

INSTRUCTION;)1' I

INSTRUCTION

 

 

 

 

 

 

POINTER

 

-8

 

 

 

CS SELECTOR

 

 

POINTER (19-16) 0

OPCODE (10-0)

 

 

 

 

 

 

OPERAND {

 

 

DATA POINTER (15-0)

 

·10

 

 

 

DATA OPERAND OFFSET

POINTER

 

DATA POINTER I

 

 

 

 

 

 

 

 

 

 

0

 

.12

 

 

DATA OPERAND SELECTOR

 

 

(19-16)

 

 

 

 

 

 

 

 

 

 

 

 

 

SIGNIFICAND 15-0

+14

 

 

 

 

SIGNIFICAND 15-0

 

 

 

SIGNIFICAND 31·16

+1.

 

 

 

 

51GNIFICAND 31·16

TOPSTA

 

 

SIGNIFICAND 47·32

+\8

 

TOP STA

 

 

SIGNIFICANO 47·32

ELEMENT;ST

 

 

 

 

 

 

 

 

ELEMENT :ST

 

 

 

 

'"{

SIGNIFICAND 63·48

+20

 

 

'"{

SIGNIFICAND 63·48

 

 

s\

 

EXPONENT 14·0

+22

 

 

 

5\

 

EXPONENT 14-0

 

 

 

SIGNIFICAND 15·0

+2'

 

 

 

 

SIGNIFICAND 15-0

 

 

L

 

 

+2.

 

 

 

L

 

 

 

 

SIGNIFICANO 31·16

 

 

 

 

SIGNIFICAND 31·16

NEXTSTAC K

 

51GNIFICAND 47·32

+28

 

NEXT STAC K

 

SIGNIFICAND 47·32

ELEMENT:ST(1 )

 

 

ElEMENT:ST(I)

 

 

 

 

SIGNIFICAND 63·48

+30

 

 

 

 

SIGNIFICAND 63·48

 

 

 

 

EXPONENT 14·0

+32

 

 

 

 

 

EXPONENT 14-0

 

 

 

SIGNIFICAND 15·0

+84

 

 

 

 

SIGNIFICAND 15-0

 

 

 

SIGNIFICAND 31-16

+8.

 

 

 

 

SlGNIF1CAND 31·16

LAST STAC

 

SIGNIFfCAND 47·32

+88

 

LAST STA

 

SIGNIFICAND 47·32

ELEMENT:ST~{

 

ELEMENT:ST(7)'"{

SIGNIFICAND 63·48

+90

 

SIGNIFICAND 63·48

 

 

Sl

 

EXpm~Em 14-0

+92

 

 

 

5\

 

EXPONENT 14-0

REAL MODE

PROTECTED MODE

 

NOTES:

 

S= Sign

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

.INCREASING ADDRESSES1

-0

+4

+6

+8

+10

+12

+14

+1.

+18

+20

+22

+"

+2.

+28

+30

+32

+8'

+8.

+88

+90

+92

G30108

2-18

Page 410
Image 410
Intel 80287, 80286 manual FSAVE/FRSTOR Memory Layout