Texas Instruments TMS320C3 Series, Руководство пользователя, Страница: 90 / 166

Directives That Initialize Constants
6-8
6.3 Directives That Initialize Constants
Several directives assemble values for the current section.
-
The .byte directive places one or more 8-bit values into consecutive words
in the current section. A byte in this case uses all 32 bits of the word placing
0s into the upper 24 bits.
-
The .fill directive reserves a specified number of words in the current sec-
tion with a value. The assembler advances the SPC and skips the re-
served words. When you use a label with .fill, it points to the
first word of
the reserved block.
-
The .float directive converts an expression 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 an expression value into a 16-bit
TMS320C3x floating-point constant. This format has an 8-bit exponent
and an 8-bit mantissa. The format is identical to that used by the .sfloat
directive of the TMS320C32. The upper 16 bits are not used and are filled
with 0s.
-
The .float8 directive converts an expression value into an 8-bit
TMS320C3x floating-point constant. This format has a 4-bit exponent and
a 4-bit mantissa. This format can be used for a quick logarithm approxima-
tion. The upper 24 bits are not used and are filled with 0s.
-
The .ieee directive calculates the 32-bit IEEE floating-point representation
of a single precision floating-point value.
-
The .int directive places one or more 16-bit values into consecutive words
in the current section. The upper 16 bits are not used and are filled with
0s.
-
The .long directive places one or more 32-bit values into consecutive by-
tes in the current section.
-
The .pfloat16 directive converts an expression value into a 16-bit floating-
point constant. The values are packed into consecutive fields of memory.
-
The .pfloat8 directive converts an expression value into an 8-bit floating-
point constant. The values are packed into consecutive fields of memory.
-
The .q xx directive places one or more 16-bit, signed 2s-complement val-
ues into consecutive words in the current section. Note that the decimal
point is displaced
xx places from the LSB (least significant bits.)