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CHAPTER 3 CPU ARCHITECTURE
User’s Manual U15798EJ2V0UD
3.4.8 Based indexed addressing
[Function]
The B or C register contents specified in an instruction are added to the contents of the base register, that is,
the HL register pair in an instruction word of the register bank specified with the register bank select flag (RBS0
and RBS1) and the sum is used to address the memory. Addition is performed by expanding the B or C register
contents as a positive number to 16 bits. A carry from the 16th bit is ignored. This addressing can be carried
out for all the memory spaces.
[Operand format]
Identifier
Description
—
[HL + B], [HL + C]
[Description example]
In the case of MOV A, [HL + B] (when selecting B register)
Operation code
1 0 1 0 1 0 1 1
[Illustration]
HL
16
0
8 7
H
L
A
7
0
7
0
Memory
The contents of the addressed
memory are transferred
7
0
+
B
Содержание mPD780344 Series
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