Ldfcond – Texas Instruments TMS320C3x User Manual

Page 573

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Load Floating-Point Value Conditionally

LDFcond

13-115

Assembly Language Instructions

Syntax

LDF

cond src, dst

Operation

If

cond is true:

src

dst.

Else:

dst is unchanged.

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 1 0 0

cond

dst

src

G

Description

If the condition is true, the

src operand is loaded into the dst register; otherwise,

the

dst register is unchanged. The dst and src operands are assumed to be

floating-point numbers.

The ’C3x provides 20 condition codes that can be used with this instruction
(see Table 13–12 on page 13-30 for a list of condition mnemonics, condition
codes, and flags). Note that an LDFU (load floating-point unconditionally) in-
struction is useful for loading R7–R0 without affecting condition flags. Condi-
tion flags are set on a previous instruction only when the destination register
is one of the extended-precision registers (R7–R0) or when one of the com-
pare instructions (CMPF, CMPF3, CMPI, CMPI3, TSTB, or TSTB3) is ex-
ecuted.

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.

Mode Bit

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