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6740h
Address Space
4766h
50D0h
PC
21038h
21036h
21034h
21038h
+56740h
77778h
Before:
Address Space
After:
PC
xxxxh
xx45h
7777Ah
77778h
xxxxh
xx77h
7777Ah
77778h
32h
+45h
77h
src
dst
Sum
xxxxh
xx32h
3579Eh
3579Ch
xxxxh
xx32h
3579Eh
3579Ch
18C5h
21032h
xxxxh
2103Ah
6740h
4766h
50D0h
21038h
21036h
21034h
18C5h
21032h
xxxxh
2103Ah
21036h
+14766h
3579Ch
Addressing Modes
4.4.4 Absolute Mode
The Absolute mode uses the contents of the word following the instruction as the address of the operand.
The Absolute mode has two addressing possibilities:
•
Absolute mode in lower 64-KB memory
•
MSP430X instruction with Absolute mode
4.4.4.1
Absolute Mode in Lower 64 KB
If an MSP430 instruction is used with Absolute addressing mode, the absolute address is a 16-bit value
and, therefore, points to an address in the lower 64 KB of the memory range. The address is calculated as
an index from 0 and is stored in the word following the instruction The RAM and the peripheral registers
can be accessed this way and existing MSP430 software is usable without modifications.
Length:
Two or three words
Operation:
The operand is the content of the addressed memory location.
Comment:
Valid for source and destination. The assembler calculates the index from 0 and
inserts it.
ADD.W &EDE,&TONI ;
Example:
This instruction adds the 16-bit data contained in the absolute source and
destination addresses and places the result into the destination.
Source:
Word at address EDE
Destination:
Word at address TONI
108
CPUX
SLAU272C – May 2011 – Revised November 2013
Copyright © 2011–2013, Texas Instruments Incorporated