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APPENDIX
G
Accumulator indirect addressing (@A)
Memory is accessed using the address indicated by the contents of the low-order bytes (16 bits) of the
accumulator (AL). Address bits 16 to 23 are specified by a mnemonic in the data bank register (DTB).
Figure A.4-10 Example of accumulator indirect addressing (@A)
MOVW A, @A
G
Accumulator indirect branch addressing (@A)
The address of the branch destination is the content (16 bits) of the low-order bytes (AL) of the
accumulator. It indicates the branch destination in the bank address space. Address bits 16 to 23 are
specified by the program bank register (PCB). For the Jump Context (JCTX) instruction, however, address
bits 16 to 23 are specified by the data bank register (DTB). This addressing is used for unconditional
branch instructions.
Figure A.4-11 Example of accumulator indirect branch addressing (@A)
JMP @A
632
(This instruction reads data by accumulator indirect addressing and stores it in A.)
Before execution
A
0 7 1 6
DTB
B B
After execution
A
0 7 1 6
DTB
B B
(This instruction causes an unconditional branch by accumulator indirect branch
addressing.)
Before execution
PC
3 C 2 0
A
6 6 7 7
After execution
PC
3 B 2 0
A
6 6 7 7
2 5 3 4
Memory space
BB2535H
BB2534H
F F E E
PCB
4 F
Memory space
3 B 2 0
4F3C20H
4F3B20H
Next instruction
PCB
4 F
3 B 2 0
F F
E E
6 1
JMP @A
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