Absf||stf – Texas Instruments TMS320C3x User Manual

Page 500

Advertising
background image

ABSF||STF

Parallel ABSF and STF

13-42

Syntax

ABSF

src2, dst1

||

STF

src3, dst2

Operation

|

src2 |

dst1

||

src3

dst2

Operands

src2

indirect (

disp = 0, 1, IR0, IR1)

dst1

register (R

n1, 0

n1

7)

src3

register (R

n2, 0

n2

7)

dst2

indirect (

disp = 0, 1, IR0, IR1)

This instruction’s operands have been augmented in the following devices:

-

’C31 silicon revision 6.0 or greater

-

’C32 silicon revision 2.0 or greater

src2

indirect (

disp = 0, 1, IR0, IR1) or any CPU register

dst1

register (R

n1, 0

n1

7)

src3

register (R

n2, 0

n2

7)

dst2

indirect (

disp = 0, 1, IR0, IR1)

Opcode

31

24 23

16

8 7

0

15

1 1 0 0 1 0

dst1

src2

dst2

0

src3

0 0 0

Description

A floating-point absolute value and a floating-point store are performed in paral-
lel. All registers are read at the beginning and loaded at the end of the execute
cycle. If one of the parallel operations (STF) reads from a register and the opera-
tion being performed in parallel (ABSF) writes to the same register, STF accepts
the contents of the register as input before it is modified by the ABSF.

If

src2 and dst2 point to the same location, src2 is read before the write to dst2.

If

src3 and dst1 point to the same register, src3 is read before the write to dst1.

An overflow occurs if

src (man) = 80000000h and src (exp) = 7Fh. The result

is

dst (man) = 7FFFFFFFh and dst (exp) = 7Fh.

Cycles

1

Status Bits

LUF

Unaffected

LV

1 if a floating-point overflow occurs; unchanged otherwise

UF

0

N

0

Z

1 if a 0 result is generated; 0 otherwise

V

1 if a floating-point overflow occurs; 0 otherwise

C

Unaffected

Advertising