CL-PS7500FE View Datasheet(PDF) - Cirrus Logic
Part Name
Description
Manufacturer
CL-PS7500FE Datasheet PDF : 251 Pages
| |||
CL-PS7500FE
System-on-a-Chip for Internet Appliance
18.3.5 Packed Decimal (P)
31
0
First
word
sign
e3
e2
e1
e0
d18
d17
d16
Second
word
d15
d14
d13
d12
d11
d10
d9
d8
Third
word
d7
d6
d5
d4
d3
d2
d1
d0
q the value is ± d × 10^(± e)
q d18 and e3 are the most significant digits of d and e respectively
q sign contains both the number's sign (bit 31) and the exponent's sign (bit 30). The other bits (29,28) are 0
q the value of d is arranged with the decimal point between d18 and d17, and is normalized so that for an ordi-
nary number 1 ≤ d18 ≤ 9
q the guaranteed ranges for d and e are 17 and 3 digits respectively: e3 and d0, d1 may always be zero in a
particular system.
q the result is undefined if any of the packed digits is hexadecimal A through F
Packed Decimal Values
Table 18-3. Packed Decimal Values
Quiet NaN
Signalling NaN
± Infinity
± Zero
Number
Sign
(top bit)
Sign
(next bit)
Exponent
Digit values
x
x
FFFF
d18 > 7, rest non-zero
x
x
FFFF
d18 < 8, rest non-zero
0,1
x
FFFF
all 0
0,1
0
0000
all 0
0,1
0,1
0000-9999 1-9.999999999999999999
All other combinations are undefined.
18.3.6 Expanded Packed Decimal (EP)
31
0
First
word
sign
e6
e5
e4
e3
e12
e1
e0
Second
word
d23
d22
d21
d20
d19
d18
d17
d16
Third
word
d15
d14
d13
d12
d11
d10
d9
d8
d7
d6
d5
d4
d3
d2
d1
d0
q Value is ± d × 10^(± e).
q d23 and e6 are the most significant digits of d and e respectively.
q Sign contains both the number's sign (bit 31) and the exponent's sign (bit 30). The other bits (29,28) are 0.
June 1997
ADVANCE DATA BOOK v2.0
FLOATING-POINT COPROCESSOR PROGRAMMER’S
MODEL
163
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