Texas Instruments TMS320C3x - Manual (Page 107)

Integer Formats
5-2
5.1 Integer Formats
The ’C3x supports two integer formats: a 16-bit short-integer format and a
32-bit single-precision integer format.
Note:
When extended-precision registers are used as integer operands, only bits
31–0 are used; bits 39–32 remain unchanged.
5.1.1 Short-Integer Format
The short-integer format is a 16-bit 2s-complement integer format for immediate-
integer operands. For those instructions that assume integer operands, this
format is sign-extended to 32 bits (see Figure 5–1). The range of an integer
si, represented in the short-integer format, is –2
15 ≤
si
≤
2 15 – 1. In Figure 5–1,
s = signed bit.
Figure 5–1. Short-Integer Format and Sign-Extension of Short Integers
15 0
15 16 31 0
Sign-extension of a short integer
s s s s s s s s s s s s s s s s
s
Short-integer format
s
5.1.2 Single-Precision Integer Format
In the single-precision integer format, the integer is represented in 2s-comple-
ment notation. The range of an integer
sp, represented in the single-precision
integer format, is – 2 31 ≤
sp
≤
2 31 – 1. Figure 5–2 shows the single-precision
integer format.
Figure 5–2. Single-Precision Integer Format
31 0
s