Freescale Semiconductor SC140 Move Two Fractional Words from MOVE.2F, Description

Models: SC140

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MIN2

MOVE.2F

Move Two Fractional Words from MOVE.2F

 

Memory to a Register Pair (AGU)

Operation

Assembler Syntax

(EA) → Da:Db

MOVE.2F (EA),Da:Db {0 EA < 232,L}

Description

MOVE.2F (EA),Da:Db

Moves two signed fractional words from memory to a data register pair (Da:Db). The effective memory address of the two words is contained in an address register with an optional offset or post-increment (EA). Each word is written in the HP of its respective data register, sign-extended, and the LP is zero-filled. The reverse operation (moving from a register pair to memory) is done with saturation. It is described in MOVES.2F.

The first operand (Da) will be moved from the lower memory address (EA). The second operand (Db) will be moved from memory address (EA + 2). In order to maintain this behavior in both big endian and little endian modes, the core will interpret the data bus differently in each mode. See Section 2.4.1, “SC140 Endian Support,” on page 2-56, for more detail on bus and memory behavior for each mode.

The address register values used with this instruction must be a multiple of 4, long aligned.

 

39

32

16

0

Da

 

SIGN

(EA) OPERAND

ZERO FILL

 

EXTENSION

 

 

Db

 

SIGN

(EA+2) OPERAND

ZERO FILL

 

EXTENSION

 

 

Status and Conditions that Affect Instruction

Register Address

Bit Name

Description

MCTL[31:0]

AM3–AM0

Address modification bits when updating R0–R7. Otherwise, the

 

 

instruction is not affected by MCTL.

EMR[16]

BEM

Set if big endian mode, cleared if little endian mode.

Status and Conditions Changed by Instruction

Register Address

Bit Name

Description

Ln

L

Clears the Ln bit in the destination registers.

Example

move.2f (r7),d2:d3

Register/Memory Address

MCTL

R7

BeforeAfter

$0000 0000

$0000 0050

A-254

SC140 DSP Core Reference Manual

Page 568
Image 568
Freescale Semiconductor SC140 Move Two Fractional Words from MOVE.2F, Memory to a Register Pair AGU, Description