Texas Instruments TMS320C54x, Руководство пользователя

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.float/.xfloat
Initialize Floating-Point Value
4-50
Syntax
.float value
1
[, ... , value
n
]
.xfloat value
1
[, ... , value
n
]
Description The .float and .xfloat directives place the floating-point representation of one
or more floating-point constants into the current data section. The
value must
be a floating-point constant or a symbol that has been equated to a floating-
point constant. Each constant is converted to a floating-point value in IEEE
single-precision 32-bit format. Floating-point constants are aligned on the
long-word boundaries unless the .xfloat directive is used. The .xfloat directive
performs the same function as the .float directive but does not align the result
on the long word boundary.
The 32-bit value consists of three fields:
Field Meaning
s A 1-bit sign field
e An 8-bit biased exponent
f A 23-bit fraction
The value is stored most significant word first, least significant word second,
in the following format:
s e f
31 30 23 22 0
When you use .float in a .struct/.endstruct sequence, .float defines a member’s
size; it does not initialize memory. For more information about .struct/
.endstruct, see Section 4.9,
Assembly-Time Symbol Directives, on page 4-21.
Example This example shows the .float directive.
1 000000 E904 .float –1.0e25
000001 5951
2 000002 4040 .float 3
000003 0000
3 000004 42F6 .float 123
000005 0000