Texas Instruments TMS320C3 Series, User Manual, Page: 103 / 166

Initialize TMS320C3x Floating-Point Value
.float, .float16, .float8, .pfloat16, .pfloat8
6-21 Assembler Directives
Syntax .float
value
1
[
,..., value
n
]
.float16
value
1
[
,..., value
n
]
.float8
value
1
[ ,..., value
n
]
.pfloat16 value
1
[ ,..., value
n
]
.pfloat8 value
1
[ ,..., value
n
]
Description These directive convert one or more values into TMS320C3x floating-point
constants.
-
The .float directive converts a value into a 32-bit TMS320C3x floating-
point constant. This format has an 8-bit exponent and a 24-bit mantissa.
-
The .float16 directive converts a
value into a 16-bit TMS320C3x floating-
point constant. This format has an 8-bit exponent and an 8-bit mantissa.
-
The .float8 directive converts a value into an 8-bit TMS320C3x floating-
point constant. This format has a 4-bit exponent and a 4-bit mantissa.
When properly scaled, this format can be used for quick logarithm approxi-
mations.
-
The .pfloat16 directive converts a value into a 16-bit floating-point
constant. The values are packed into consecutive fields of memory.
-
The .pfloat8 directive converts a value into an 8-bit floating-point
constant. The values are packed into consecutive fields of memory.
The
value is a required parameter; it is an expression that is evaluated and
placed in the constant. The value must be absolute.
Note that the ’C31 expects floating-point numbers to have the 32-bit format.
Example Here is an example of these directives.
PI .set 3.1415926 ;.set remembers PI is float
.float –10/3, –0.1, 0, 0.1, PI,2*PI ;Some easy to compare values
.float8 –10/3, –0.1, 0, 0.1, PI,2*PI ;
.pfloat8 –10/3, –0.1, 0, 0.1, PI,2*PI ;
.float16 –10/3, –0.1, 0, 0.1, PI,2*PI ;
.pfloat16 –10/3, –0.1, 0, 0.1, PI,2*PI ;
.ieee –10/3, –0.1, 0, 0.1, PI,2*PI ;