Based Addressing - NEC mPD780024AS Series Preliminary User's Manual

3.4.7 Based addressing

[Function]
8-bit immediate data is added as offset data 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 offset data 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 example]
MOV A, [HL + 10H]; when setting byte to 10H
CHAPTER 3 CPU ARCHITECTURE
— [HL + byte]
Operation code
Preliminary User's Manual U16035EJ1V0UM
Description
1 0 1 0 1 1 1 0
0 0 0 1 0 0 0 0
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