Texas Instruments TMS320C64X manual Using Dsplib, 1. Dsplib Data Types

Using DSPLIB

2.2 Using DSPLIB

2.2.1DSPLIB Arguments and Data Types

2.2.1.1DSPLIB Types

Table 2−1 shows the data types handled by the DSPLIB.

Table 2−1. DSPLIB Data Types

	Size
Name	(bits)	Type	Minimum	Maximum
short	16	integer	−32768	32767
int	32	integer	−2147483648	2147483647
long	40	integer	−549755813888	549755813887
pointer	32	address	0000:0000h	FFFF:FFFFh
Q.15	16	fraction	−0.9999694824...	0.9999694824...
Q.31	32	fraction	−0.99999999953...	0.99999999953...
IEEE float	32	floating point	1.17549435e−38	3.40282347e+38
IEEE double	64	floating point	2.2250738585072014e−308	1.7976931348623157e+308

Unless specifically noted, DSPLIB operates on Q.15-fractional data type elements. Appendix A presents an overview of Fractional Q formats.

2.2.1.2DSPLIB Arguments

TI DSPLIB functions typically operate over vector operands for greater efficiency. Even though these routines can be used to process short arrays, or even scalars (unless a minimum size requirement is noted), they will be slower for those cases.

-Vector stride is always equal to 1: Vector operands are composed of vector elements held in consecutive memory locations (vector stride equal to 1).

-Complex elements are assumed to be stored in consecutive memory locations with Real data followed by Imaginary data.

-In-place computation is not allowed, unless specifically noted: Source operand cannot be equal to destination operand.

Installing and Using DSPLIB 2-3