Texas Instruments TMS320C3x User Manual

Page 128

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Floating-Point Conversion (IEEE Std. 754)

5-23

Data Formats and Floating-Point Operation

Example 5–6.TMS320C3x-to-IEEE Conversion (Fast Version) (Continued)

*

CYCLES: 14 (WORST CASE)

WORDS: 15

*

.global

TOIEEE

*
TOIEEE

LDF

R0,R0

;

Determine the sign of the number

LDFZ

*+AR1(4),R0

;

If 0, load appropriate number

BND

NEG

;

Branch to NEG if negative (delayed)

ABSF

R0

;

Take the absolute value of the number

LSH

1,R0

;

Eliminate the sign bit in R0

PUSHF

R0

POP

R0

;

Place number in lower 32 bits of R0

ADDI

*+AR1(2),R0

;

Add exponent bias (127)

LSH

±

1,R0

;

Add the positive sign

RETS

NEG

POP

R0

;

Place number in lower 32 bits

;

of R0

ADDI

*+AR1(2),R0

;

Add exponent bias (127)

LSH

±

1,R0

;

Make space for the sign

ADDI

*+AR1(3),R0

;

Add the negative sign

RETS

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