Texas Instruments TMS320C3x User Manual

Page 591

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Load Floating-Point Mantissa

LDM

13-133

Assembly Language Instructions

Syntax

LDM

src, dst

Operation

src (man)

dst (man)

Operands

src general addressing modes (G):

0 0

register (R

n, 0

n

7)

0 1

direct

1 0

indirect (disp = 0–255, IR0, IR1)

1 1

immediate

dst register

(R

n, 0

n

7)

Opcode

31

24 23

16

8 7

0

15

0 0 0

0 1

1

0

0

0

dst

src

G

Description

The mantissa field of the

src operand is loaded into the mantissa field of the

dst register. The dst exponent field is not modified. The src and dst operands
are assumed to be floating-point numbers. If the

src operand is from memory,

the entire memory contents are loaded as the mantissa. If immediate address-
ing mode is used, bits 15–12 of the instruction word are forced to 0 by the as-
sembler.

Cycles

1

Status Bits

LUF

Unaffected

LV

Unaffected

UF

Unaffected

N

Unaffected

Z

Unaffected

V

Unaffected

C

Unaffected

OVM

Operation is not affected by OVM bit value.

Example

LDM 156.75,R2 (156.75 = 071CC00000h)

Before Instruction

After Instruction

R2

00 0000 0000

R2

00 1CC0 0000

LUF

0

LUF

0

LV

0

LV

0

UF

0

UF

0

N

0

N

0

Z

0

Z

0

V

0

V

0

C

0

C

0

1.22460938e+00

Mode Bit

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