Addressing Modes — EXT

Instructions that use extended addressing can read from or write to any location in the 68HC05 memory map.

Extended addressing is often used with LDA, LDX, STA, and STX…

LDA $4000 STX $0130

As well as with ADC, ADD, SBC, and SUB for arithmetic operations…

SBC $01F1

…CMP, CPX, and BIT for register comparison and memory testing…

CMP $08C3

…with AND, EOR, and ORA for combinatorial logic…

EOR $0325

And with JMP and JSR for program flow changes…

JMP $1200 JSR $3040

98/06/10

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Notes:

Extended addressing allows any location in the 68HC05 memory map to be read from or written to using a single instruction. The address is always specified using a 16-bit value.

All instructions that use extended mode addressing require three bytes of program storage, one for the opcode and two for the operand.