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Texas Instruments TMS320C67X/C67X+ DSP User Manual

Page 264

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RSQRSP

Single-Precision Floating-Point Square-Root Reciprocal Approximation

3-204

Instruction Set

SPRU733

Note:
1) If src2 is SNaN, NaN_out is placed in dst and the INVAL and NAN2 bits

are set.

2) If src2 is QNaN, NaN_out is placed in dst and the NAN2 bit is set.

3) If src2 is a negative, nonzero, nondenormalized number, NaN_out is

placed in dst and the INVAL bit is set.

4) If src2 is a signed denormalized number, signed infinity is placed in dst

and the DIV0, INEX, and DEN2 bits are set.

5) If src2 is signed 0, signed infinity is placed in dst and the DIV0 and INFO

bits are set. The Newton-Rhapson approximation cannot be used to
calculate the square root of 0 because infinity multiplied by 0 is invalid.

6) If src2 is positive infinity, positive 0 is placed in dst.

Pipeline
Stage

E1

Read

src2

Written

dst

Unit in use

.S

Instruction Type

Single-cycle

Delay Slots

0

Functional Unit
Latency

1

See Also

RCPSP, RSQRDP

Example 1

RSQRSP .S1 A1,A2

Before instruction

1 cycle after instruction

A1 4080 0000h

4.0

A1 4080 0000h

4.0

A2 xxxx xxxxh

A2 3F00 0000h

0.5

Example 2

RSQRSP .S2X A1,B2

Before instruction

1 cycle after instruction

A1 4109 999Ah

8.6

A1 4109 999Ah

8.6

B2 xxxx xxxxh

B2 3EAE 8000h

0.34082031

Pipeline