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Instruction Set Description
4.6.3.17 MOVX
MOVX.A
Move source address-word to destination address-word
MOVX.[W]
Move source word to destination word
MOVX.B
Move source byte to destination byte
MOVX.A src,dst
Syntax
MOVX src,dst
or
MOVX.W src,dst
MOVX.B src,dst
Operation
src
→
dst
Description
The source operand is copied to the destination. The source operand is not affected.
Both operands may be located in the full address space.
Status Bits
N:
Not affected
Z:
Not affected
C:
Not affected
V:
Not affected
Mode Bits
OSCOFF, CPUOFF, and GIE are not affected.
Example
Move a 20-bit constant 18000h to absolute address-word EDE
MOVX.A
#018000h,&EDE
; Move 18000h to EDE
Example
The contents of table EDE (word data, 20-bit addresses) are copied to table TOM. The
length of the table is 030h words.
MOVA
#EDE,R10
; Prepare pointer (20-bit address)
Loop
MOVX.W
@R10+,TOM-EDE-2(R10)
; R10 points to both tables.
; R10+2
CMPA
#EDE+60h,R10
; End of table reached?
JLO
Loop
; Not yet
...
; Copy completed
Example
The contents of table EDE (byte data, 20-bit addresses) are copied to table TOM. The
length of the table is 020h bytes.
MOVA
#EDE,R10
; Prepare pointer (20-bit)
MOV
#20h,R9
; Prepare counter
Loop
MOVX.W
@R10+,TOM-EDE-2(R10)
; R10 points to both tables.
; R10+1
DEC
R9
; Decrement counter
JNZ
Loop
; Not yet done
...
; Copy completed
Ten of the 28 possible addressing combinations of the MOVX.A instruction can use the
MOVA instruction. This saves two bytes and code cycles. Examples for the addressing
combinations are:
MOVX.A
Rsrc,Rdst
MOVA
Rsrc,Rdst
; Reg/Reg
MOVX.A
#imm20,Rdst
MOVA
#imm20,Rdst
; Immediate/Reg
MOVX.A
&abs20,Rdst
MOVA
&abs20,Rdst
; Absolute/Reg
MOVX.A
@Rsrc,Rdst
MOVA
@Rsrc,Rdst
; Indirect/Reg
MOVX.A
@Rsrc+,Rdst
MOVA
@Rsrc+,Rdst
; Indirect,Auto/Reg
MOVX.A
Rsrc,&abs20
MOVA
Rsrc,&abs20
; Reg/Absolute
202
CPUX
SLAU272C – May 2011 – Revised November 2013
Copyright © 2011–2013, Texas Instruments Incorporated