TFR

TFR

Transfer Data Register to Data Register (DALU)

TFR

Operation

Assembler Syntax

 

Da → Dn

TFR Da,Dn

 

Description

TFR Da,Dn

Copies a source data register (Da) to a destination data register (Dn). The Ln bit is re-calculated (not copied) in the destination register. Saturation mode is ignored and no saturation is done.

Status and Conditions that Affect Instruction

Register Address

Bit Name

Description

SR[5:4]

S[1:0]

Scaling bits determine which bits in the result are used in the Ln bit

 

 

calculation.

Status and Conditions Changed By Instruction

Register Address

Bit Name

Description

Ln

L

Calculates and updates the Ln bit in the destination register.

Example 1

tfr d15,d14

Register/Memory Address

SR

D15

L14:D14

Before

$00E0 0000

$FF F23A 1422

After

$0:$FF F23A 1422

Example 2

tfr d7,d6

Register/Memory Address

SR

D7

D6

Before

$00E0 0020

$00 5000 0000

After

$1:$00 5000 0000

Scaling up set by SR[5}, so L6 bit is set by bit 30 overflow.

A-404

SC140 DSP Core Reference Manual

Page 718
Image 718
Freescale Semiconductor SC140 specifications Transfer Data Register to Data Register Dalu, Tfr d15,d14, Tfr d7,d6