A.2.3 Q.31 Format; A−3 Q.31 Low Memory Location Bit Fields; A−4 Q.31 High Memory Location Bit Fields - Texas Instruments TMS320C64X Programmer's Reference Manual

Fractional Q Formats

A.2.3 Q.31 Format

Table A−3. Q.31 Low Memory Location Bit Fields
Table A−4. Q.31 High Memory Location Bit Fields
A-4
Q.31 format spans two 16-bit memory words. The 16-bit word stored in the
lower memory location contains the 16 least significant bits, and the higher
memory location contains the most significant 15 bits and the sign bit. The
approximate allowable range of numbers in Q.31 representation is (−1,1) and
the finest fractional resolution is 2
Bit 15 14
Value Q15 Q14
Bit 15 14
Value S Q30
= 4.66 × 10
−31
...
13 12
...
Q13 Q12
...
13 12
...
Q29 Q28
−10
.
3 2 1
Q3 Q2 Q1
3 2 1
Q19 Q18 Q17
0
Q0
0
Q16