xxxxh
Address Space
7778h
579Ch
PC
2103Ah
21038h
21036h
Before:
Address Space
After:
5292h
21034h
xxxxh
7778h
579Ch
PC
2103Ah
21038h
21036h
5292h
21034h
xxxxh
2345h
0777Ah
07778h
xxxxh
7777h
0777Ah
07778h
5432h
+2345h
7777h
src
dst
Sum
xxxxh
5432h
0579Eh
0579Ch
xxxxh
5432h
0579Eh
0579Ch
Addressing Modes
135
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
CPUX
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 2 addressing possibilities:
•
Absolute mode in lower 64KB memory
•
MSP430X instruction with absolute mode
4.4.4.1
Absolute Mode in Lower 64KB
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 64KB 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:
2 or 3 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.
Example:
ADD.W &EDE,&TONI ;
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